dwa

core/src/main/java/art/arcane/iris/core/IrisSettings.java

@@ -276,7 +276,13 @@ public class IrisSettings {
         public boolean useCustomColorsIngame = true;
         public boolean adjustVanillaHeight = false;
         public boolean autoIngestDatapacks = true;
-        public boolean autoImportDatapackStructures = true;
+        /**
+         * Converting every registered datapack structure into editable Iris resources writes
+         * thousands of objects/pools/pieces into the pack folder. Native generation and
+         * nativeStructures placements never need those copies, so this stays opt-in; run
+         * /iris structure import <dimension> when you actually want editable copies.
+         */
+        public boolean autoImportDatapackStructures = false;
         /** Unresolved pack content keys and bad block-state properties become blocking pack errors. -Diris.strictContent overrides. */
         public boolean strictContentKeys = false;
         public int spinh = -20;

core/src/main/java/art/arcane/iris/core/IrisWorldStorage.java

@@ -7,19 +7,64 @@ import org.bukkit.World;
 import org.bukkit.generator.WorldInfo;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Path;
 import java.util.Locale;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Properties;
 
 public final class IrisWorldStorage {
     private static final String IRIS_NAMESPACE = "iris";
+    private static final String DEFAULT_LEVEL_NAME = "world";
+
+    /**
+     * Server#getLevelDirectory is Paper-API-only. Once a call throws NoSuchMethodError (plain
+     * Spigot/CraftBukkit) this flips and every later call goes straight to the fallback.
+     */
+    private static volatile boolean levelDirectoryUnavailable;
+    private static volatile String cachedFallbackLevelName;
 
     private IrisWorldStorage() {
     }
 
     public static File levelRoot() {
-        return Bukkit.getServer().getLevelDirectory().toAbsolutePath().normalize().toFile();
+        if (!levelDirectoryUnavailable) {
+            try {
+                return Bukkit.getServer().getLevelDirectory().toAbsolutePath().normalize().toFile();
+            } catch (NoSuchMethodError e) {
+                levelDirectoryUnavailable = true;
+            }
+        }
+        return new File(Bukkit.getWorldContainer(), fallbackLevelName()).getAbsoluteFile();
+    }
+
+    private static String fallbackLevelName() {
+        String cached = cachedFallbackLevelName;
+        if (cached == null) {
+            cached = levelNameFromProperties(new File("server.properties"));
+            cachedFallbackLevelName = cached;
+        }
+        return cached;
+    }
+
+    static String levelNameFromProperties(File serverProperties) {
+        Properties properties = new Properties();
+        if (Objects.requireNonNull(serverProperties, "serverProperties").isFile()) {
+            try (InputStream in = new FileInputStream(serverProperties)) {
+                properties.load(in);
+            } catch (IOException ignored) {
+                // Unreadable server.properties: fall through to the default level name.
+            }
+        }
+        return levelNameFromProperties(properties);
+    }
+
+    static String levelNameFromProperties(Properties properties) {
+        String levelName = Objects.requireNonNull(properties, "properties").getProperty("level-name", DEFAULT_LEVEL_NAME).trim();
+        return levelName.isEmpty() ? DEFAULT_LEVEL_NAME : levelName;
     }
 
     public static File levelRoot(File dimensionRoot) {

core/src/main/java/art/arcane/iris/core/IrisWorlds.java

@@ -1,6 +1,7 @@
 package art.arcane.iris.core;
 
 import art.arcane.iris.core.loader.IrisData;
+import art.arcane.iris.core.pack.PackDownloader;
 import art.arcane.iris.core.service.StudioSVC;
 import art.arcane.iris.engine.data.cache.AtomicCache;
 import art.arcane.iris.engine.object.IrisDimension;
@@ -159,6 +160,12 @@ public class IrisWorlds {
             dimension = IrisData.loadAnyDimension(id, null);
         }
         if (dimension == null) {
+            File packsRoot = IrisPlatforms.get().dataFolderNoCreate(StudioSVC.WORKSPACE_NAME);
+            if (PackDownloader.isPackPresent(packsRoot, id)) {
+                IrisLogging.error("Pack '" + id + "' exists at " + new File(packsRoot, id).getPath()
+                        + " but its dimension failed to load; not redownloading. Fix or delete the pack folder.");
+                return null;
+            }
             IrisLogging.warn("Unable to find dimension type " + id + " Looking for online packs...");
             IrisServices.get(StudioSVC.class).downloadSearch(new VolmitSender(Bukkit.getConsoleSender()), id, false);
             dimension = IrisData.loadAnyDimension(id, null);

core/src/main/java/art/arcane/iris/core/ServerConfigurator.java

@@ -363,6 +363,7 @@ public class ServerConfigurator {
         File[] packs = IrisPlatforms.get().dataFolder("packs").listFiles(File::isDirectory);
         Stream<File> locals = packs == null ? Stream.empty() : Arrays.stream(packs);
         return Stream.concat(locals
+                .filter(base -> !base.getName().contains(".importing-"))
                 .filter( base -> {
                     var content = new File(base, "dimensions").listFiles();
                     return content != null && content.length > 0;

core/src/main/java/art/arcane/iris/core/WorldCreatorCompat.java

@@ -0,0 +1,47 @@
+package art.arcane.iris.core;
+
+import org.bukkit.NamespacedKey;
+import org.bukkit.WorldCreator;
+
+/**
+ * WorldCreator.ofKey and WorldCreator#key are Paper-API-only. Once a call throws
+ * NoSuchMethodError (plain Spigot/CraftBukkit) this flips and every later call goes
+ * straight to the fallback. The fallback derives names/keys through IrisWorldStorage's
+ * logical mapping so keyFromName(creator.name()) round-trips on Spigot.
+ */
+public final class WorldCreatorCompat {
+    private static volatile boolean keyedCreatorsUnavailable;
+
+    private WorldCreatorCompat() {
+    }
+
+    public static WorldCreator ofKey(NamespacedKey worldKey) {
+        if (!keyedCreatorsUnavailable) {
+            try {
+                return WorldCreator.ofKey(worldKey);
+            } catch (NoSuchMethodError e) {
+                keyedCreatorsUnavailable = true;
+            }
+        }
+        return new WorldCreator(IrisWorldStorage.logicalName(worldKey));
+    }
+
+    public static NamespacedKey keyOf(WorldCreator creator) {
+        if (!keyedCreatorsUnavailable) {
+            try {
+                return creator.key();
+            } catch (NoSuchMethodError e) {
+                keyedCreatorsUnavailable = true;
+            }
+        }
+        return IrisWorldStorage.keyFromName(creator.name());
+    }
+
+    static String fallbackName(NamespacedKey worldKey, String levelName) {
+        return IrisWorldStorage.logicalName(worldKey, levelName);
+    }
+
+    static NamespacedKey fallbackKey(String creatorName, String levelName) {
+        return IrisWorldStorage.keyFromName(creatorName, levelName);
+    }
+}

core/src/main/java/art/arcane/iris/core/datapack/DatapackIngestService.java

@@ -145,7 +145,7 @@ public final class DatapackIngestService {
 
         if (report.changed()) {
             message(sender, C.YELLOW + "New datapack structures were installed. A server restart is required for them to register and generate.");
-            message(sender, C.GRAY + "After the restart their jigsaw pools, pieces & objects are imported automatically (set general.autoImportDatapackStructures=false to disable), or run /iris structure import <dimension> to import everything on demand. Reference an imported key from a 'structures' placement to position it manually.");
+            message(sender, C.GRAY + "After the restart they generate natively - no import needed. To get editable Iris copies (jigsaw pools, pieces & objects written into the pack) run /iris structure import <dimension>, or set general.autoImportDatapackStructures=true to do it on every ingest. Place any registered key directly with a 'structures' placement using nativeStructures.");
             message(sender, C.GRAY + "Datapacks replace matching vanilla structure keys by default. Set 'importedStructures.datapackOverrides' to false to keep minecraft-namespaced structure definitions untouched; deny non-minecraft datapack and mod structures explicitly with importedStructures.disabled.");
             if (restart) {
                 ServerConfigurator.restart();

core/src/main/java/art/arcane/iris/core/lifecycle/WorldLifecycleRequest.java

@@ -1,5 +1,6 @@
 package art.arcane.iris.core.lifecycle;
 
+import art.arcane.iris.core.WorldCreatorCompat;
 import org.bukkit.NamespacedKey;
 import org.bukkit.World;
 import org.bukkit.WorldCreator;
@@ -24,7 +25,7 @@ public record WorldLifecycleRequest(
     public static WorldLifecycleRequest fromCreator(WorldCreator creator, boolean studio, boolean benchmark, WorldLifecycleCaller callerKind) {
         return new WorldLifecycleRequest(
                 creator.name(),
-                creator.key(),
+                WorldCreatorCompat.keyOf(creator),
                 creator.environment(),
                 creator.generator(),
                 creator.biomeProvider(),
@@ -39,7 +40,7 @@ public record WorldLifecycleRequest(
     }
 
     public WorldCreator toWorldCreator() {
-        WorldCreator creator = WorldCreator.ofKey(worldKey)
+        WorldCreator creator = WorldCreatorCompat.ofKey(worldKey)
                 .environment(environment)
                 .generateStructures(generateStructures)
                 .hardcore(hardcore)

core/src/main/java/art/arcane/iris/core/localization/PackDownloadMessages.java

@@ -94,6 +94,10 @@ public final class PackDownloadMessages {
             "iris.runtime.pack_download.acquired",
             "Successfully acquired {name}."
     );
+    public static final TextKey ALREADY_INSTALLED = TextKey.of(
+            "iris.runtime.pack_download.already_installed",
+            "Pack {key} is already installed, skipping download."
+    );
     public static final TextKey VALIDATION_FAILED = TextKey.of(
             "iris.runtime.pack_download.validation_failed",
             "Pack '{pack}' failed validation; world and Studio creation will be refused. Reasons:"
@@ -136,6 +140,7 @@ public final class PackDownloadMessages {
             DIMENSION_KEY_CONFLICT,
             PACK_KEY_CONFLICT,
             ACQUIRED,
+            ALREADY_INSTALLED,
             VALIDATION_FAILED,
             VALIDATION_REASON,
             VALIDATED_WITH_WARNINGS,

core/src/main/java/art/arcane/iris/core/pack/PackDownloader.java

@@ -32,6 +32,7 @@ import org.zeroturnaround.zip.commons.FileUtils;
 import java.io.File;
 import java.io.IOException;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Consumer;
 import java.util.regex.Pattern;
 
@@ -42,6 +43,7 @@ public final class PackDownloader {
     private static final Pattern GITHUB_REPOSITORY = Pattern.compile("[A-Za-z0-9_.-]+/[A-Za-z0-9_.-]+");
     private static final Pattern GITHUB_REF = Pattern.compile("[A-Za-z0-9][A-Za-z0-9._/-]*");
     private static final Pattern COMMIT_SHA = Pattern.compile("[0-9a-fA-F]{40}");
+    private static final ConcurrentHashMap<String, Object> DOWNLOAD_LOCKS = new ConcurrentHashMap<>();
 
     private PackDownloader() {
     }
@@ -50,11 +52,51 @@ public final class PackDownloader {
         return DEFAULT_OVERWORLD_PACK.equals(pack);
     }
 
-    public static String downloadDefaultOverworld(File packsFolder, boolean forceOverwrite, Consumer<String> feedback) throws IOException {
-        return download(packsFolder, DEFAULT_OVERWORLD_REPOSITORY, defaultOverworldReleaseUrl(), forceOverwrite, true, feedback);
+    public static String defaultOverworldPack() {
+        return DEFAULT_OVERWORLD_PACK;
     }
 
-    public static String download(File packsFolder, String repo, String ref, boolean forceOverwrite, boolean directUrl, Consumer<String> feedback) throws IOException {
+    /**
+     * Whether a pack folder for {@code key} already exists with at least one dimension file.
+     * Presence is judged on disk, not on loadability: a pack that exists but fails to parse must
+     * surface as an error, never as a redownload. A folder without any dimensions/*.json is a
+     * partial import (an interrupted copy) and counts as absent so it can be replaced.
+     */
+    public static boolean isPackPresent(File packsFolder, String key) {
+        if (packsFolder == null || key == null || key.isBlank()) {
+            return false;
+        }
+        File[] dimensions = new File(new File(packsFolder, key), "dimensions")
+                .listFiles((File dir, String name) -> name.endsWith(".json"));
+        return dimensions != null && dimensions.length > 0;
+    }
+
+    public static String downloadDefaultOverworld(File packsFolder, boolean forceOverwrite, Consumer<String> feedback) throws IOException {
+        return download(packsFolder, DEFAULT_OVERWORLD_REPOSITORY, defaultOverworldReleaseUrl(), forceOverwrite, true, DEFAULT_OVERWORLD_PACK, feedback);
+    }
+
+    /**
+     * Downloads and imports a pack. {@code expectedKey} is the pack key the caller is trying to
+     * obtain (null when unknown, e.g. arbitrary repo/branch downloads); when the key is already
+     * present on disk and {@code forceOverwrite} is false, the network is never touched. The
+     * per-repo lock keeps concurrent startup triggers (async default-pack install racing world
+     * resolution) from downloading the same archive twice.
+     */
+    public static String download(File packsFolder, String repo, String ref, boolean forceOverwrite, boolean directUrl, String expectedKey, Consumer<String> feedback) throws IOException {
+        // Lock on the destination pack key when known: concurrent triggers for the same pack can
+        // arrive with different refs (release URL vs listing branch) and must still serialize.
+        String lockKey = expectedKey != null && !expectedKey.isBlank() ? "key:" + expectedKey : "ref:" + repo + "|" + ref;
+        Object lock = DOWNLOAD_LOCKS.computeIfAbsent(lockKey, key -> new Object());
+        synchronized (lock) {
+            if (!forceOverwrite && isPackPresent(packsFolder, expectedKey)) {
+                feedback.accept(IrisLanguage.plain(PackDownloadMessages.ALREADY_INSTALLED, MessageArgument.untrusted("key", expectedKey)));
+                return expectedKey;
+            }
+            return downloadLocked(packsFolder, repo, ref, forceOverwrite, directUrl, feedback);
+        }
+    }
+
+    private static String downloadLocked(File packsFolder, String repo, String ref, boolean forceOverwrite, boolean directUrl, Consumer<String> feedback) throws IOException {
         String url = directUrl ? ref : resolveGithubArchiveUrl(repo, ref);
         feedback.accept(IrisLanguage.plain(PackDownloadMessages.DOWNLOADING, MessageArgument.untrusted("url", url)) + " "); //The extra space stops a bug in adventure API from repeating the last letter of the URL
         File zip = WebCache.getNonCachedFile("pack-" + repo, url);
@@ -122,6 +164,12 @@ public final class PackDownloader {
         String key = d.getLoadKey();
         feedback.accept(IrisLanguage.plain(PackDownloadMessages.IMPORTING, MessageArgument.untrusted("name", d.getName()), MessageArgument.untrusted("key", key)));
         File packEntry = new File(packsFolder, key);
+        File[] staleStaging = packsFolder.listFiles((File parent, String name) -> name.startsWith(key + ".importing-"));
+        if (staleStaging != null) {
+            for (File stale : staleStaging) {
+                IO.delete(stale);
+            }
+        }
 
         if (forceOverwrite) {
             IO.delete(packEntry);
@@ -134,11 +182,29 @@ public final class PackDownloader {
 
         File[] existingEntries = packEntry.listFiles();
         if (packEntry.exists() && existingEntries != null && existingEntries.length > 0) {
-            feedback.accept(IrisLanguage.plain(PackDownloadMessages.PACK_KEY_CONFLICT, MessageArgument.untrusted("key", key)));
-            return null;
+            if (isPackPresent(packsFolder, key)) {
+                feedback.accept(IrisLanguage.plain(PackDownloadMessages.PACK_KEY_CONFLICT, MessageArgument.untrusted("key", key)));
+                return null;
+            }
+            // Non-empty but no dimension file: a partial import from an interrupted copy.
+            // Replace it instead of refusing forever.
+            IrisLogging.warn("Replacing partial pack folder " + packEntry.getPath() + " (no dimension files found).");
+            IO.delete(packEntry);
         }
 
-        FileUtils.copyDirectory(dir, packEntry);
+        // Stage inside the packs folder and move into place so packs/<key> is never partial:
+        // an interrupted copy previously left a folder without dimensions/, which then blocked
+        // every future import as a key conflict.
+        File staging = new File(packsFolder, key + ".importing-" + UUID.randomUUID());
+        try {
+            FileUtils.copyDirectory(dir, staging);
+            if (!staging.renameTo(packEntry)) {
+                throw new IOException("Unable to move imported pack into place: " + packEntry.getPath());
+            }
+        } catch (IOException | RuntimeException e) {
+            IO.delete(staging);
+            throw e;
+        }
 
         IrisData.getLoaded(packEntry)
                 .ifPresent(IrisData::hotloaded);

core/src/main/java/art/arcane/iris/core/project/SchemaBuilder.java

@@ -72,6 +72,8 @@ public class SchemaBuilder {
     private static final String SYMBOL_LIMIT__N = "*";
     private static final String SYMBOL_TYPE__N = "";
     private static final String MINECRAFT_NAMESPACE = "minecraft:";
+    /** Namespaced key or family/namespace prefix: "minecraft:village_plains", "minecraft:village", "nova_structures:". */
+    private static final String VANILLA_STRUCTURE_PREFIX_PATTERN = "^[a-z0-9_.-]+:[a-z0-9_./-]*$";
     private static volatile JSONArray fontTypes;
     private final KMap<String, JSONObject> definitions;
     private final Class<?> root;
@@ -249,6 +251,46 @@ public class SchemaBuilder {
         }
     }
 
+    /**
+     * A registry enum that ALSO accepts family/namespace prefixes ("minecraft:village",
+     * "nova_structures:") — the runtime prefix-matching contract of importedStructures.disabled and
+     * adjustments[].match. Emitted as anyOf(enum, pattern) so autocomplete still offers registered
+     * keys while prefix entries validate instead of being rejected.
+     */
+    private void putRegistryEnumOrPrefixRef(JSONObject target, String definitionKey,
+                                            String enumDefinitionKey, Supplier<JSONArray> values,
+                                            String pattern) {
+        if (!definitions.containsKey(definitionKey)) {
+            JSONArray anyOf = new JSONArray();
+            JSONObject enumRef = new JSONObject();
+            try {
+                putRegistryEnumRef(enumRef, enumDefinitionKey, values);
+            } catch (RuntimeException e) {
+                IrisLogging.debug("Schema enum '" + enumDefinitionKey + "' unavailable ("
+                        + e.getMessage() + "); emitting prefix pattern only");
+            }
+            if (enumRef.has("$ref")) {
+                anyOf.put(enumRef);
+            }
+            JSONObject prefix = new JSONObject();
+            prefix.put("type", "string");
+            prefix.put("pattern", pattern);
+            anyOf.put(prefix);
+            JSONObject definition = new JSONObject();
+            definition.put("anyOf", anyOf);
+            definitions.put(definitionKey, definition);
+        }
+        target.put("$ref", "#/definitions/" + definitionKey);
+    }
+
+    private void putRegistryEnumOrPrefixItems(JSONObject prop, String definitionKey,
+                                              String enumDefinitionKey, Supplier<JSONArray> values,
+                                              String pattern) {
+        JSONObject items = new JSONObject();
+        putRegistryEnumOrPrefixRef(items, definitionKey, enumDefinitionKey, values, pattern);
+        prop.put("items", items);
+    }
+
     private JSONArray itemTypes() {
         JSONArray a = new JSONArray();
         for (String key : IrisPlatforms.get().registries().itemKeys()) {
@@ -427,8 +469,14 @@ public class SchemaBuilder {
 
                 } else if (k.isAnnotationPresent(RegistryListVanillaStructure.class)) {
                     fancyType = "Vanilla Structure";
-                    putRegistryEnumRef(prop, "enum-vanilla-structure", this::vanillaStructures);
-                    description.add(SYMBOL_TYPE__N + "  Must be a valid vanilla/datapack structure key (use ctrl+space for auto complete!)");
+                    if (k.getAnnotation(RegistryListVanillaStructure.class).prefixes()) {
+                        putRegistryEnumOrPrefixRef(prop, "enum-vanilla-structure-or-prefix",
+                                "enum-vanilla-structure", this::vanillaStructures, VANILLA_STRUCTURE_PREFIX_PATTERN);
+                        description.add(SYMBOL_TYPE__N + "  Must be a vanilla/datapack structure key or a family/namespace prefix like 'minecraft:village' or 'nova_structures:' (use ctrl+space for auto complete!)");
+                    } else {
+                        putRegistryEnumRef(prop, "enum-vanilla-structure", this::vanillaStructures);
+                        description.add(SYMBOL_TYPE__N + "  Must be a valid vanilla/datapack structure key (use ctrl+space for auto complete!)");
+                    }
 
                 } else if (k.isAnnotationPresent(RegistryListVanillaStructureSet.class)) {
                     fancyType = "Vanilla Structure Set";
@@ -627,8 +675,14 @@ public class SchemaBuilder {
                                 description.add(SYMBOL_TYPE__N + "  Must be a registered vanilla, datapack, or modded template pool key (use ctrl+space for auto complete!)");
                             } else if (k.isAnnotationPresent(RegistryListVanillaStructure.class)) {
                                 fancyType = "List<Vanilla Structure>";
-                                putRegistryEnumItems(prop, "enum-vanilla-structure", this::vanillaStructures);
-                                description.add(SYMBOL_TYPE__N + "  Must be a valid vanilla/datapack structure key (use ctrl+space for auto complete!)");
+                                if (k.getAnnotation(RegistryListVanillaStructure.class).prefixes()) {
+                                    putRegistryEnumOrPrefixItems(prop, "enum-vanilla-structure-or-prefix",
+                                            "enum-vanilla-structure", this::vanillaStructures, VANILLA_STRUCTURE_PREFIX_PATTERN);
+                                    description.add(SYMBOL_TYPE__N + "  Must be a vanilla/datapack structure key or a family/namespace prefix like 'minecraft:village' or 'nova_structures:' (use ctrl+space for auto complete!)");
+                                } else {
+                                    putRegistryEnumItems(prop, "enum-vanilla-structure", this::vanillaStructures);
+                                    description.add(SYMBOL_TYPE__N + "  Must be a valid vanilla/datapack structure key (use ctrl+space for auto complete!)");
+                                }
                             } else if (k.isAnnotationPresent(RegistryListVanillaStructureSet.class)) {
                                 fancyType = "List<Vanilla Structure Set>";
                                 putRegistryEnumItems(prop, "enum-vanilla-structure-set", this::vanillaStructureSets);

core/src/main/java/art/arcane/iris/core/service/StudioSVC.java

@@ -26,7 +26,6 @@ import art.arcane.iris.core.IrisWorldStorage;
 import art.arcane.iris.core.ServerConfigurator;
 import art.arcane.iris.core.lifecycle.WorldLifecycleService;
 import art.arcane.iris.core.loader.IrisData;
-import art.arcane.iris.core.pack.IrisPack;
 import art.arcane.iris.core.pack.PackDownloader;
 import art.arcane.iris.core.pack.PackValidationRegistry;
 import art.arcane.iris.core.pack.PackValidationResult;
@@ -63,6 +62,7 @@ import java.util.function.Consumer;
 
 import art.arcane.iris.core.localization.BukkitRuntimeMessages;
 import art.arcane.iris.core.localization.IrisLanguage;
+import art.arcane.iris.core.localization.PackDownloadMessages;
 import art.arcane.volmlib.util.localization.MessageArgument;
 public class StudioSVC implements IrisService {
     public static final String LISTING = "https://raw.githubusercontent.com/IrisDimensions/_listing/main/listing-v2.json";
@@ -76,9 +76,10 @@ public class StudioSVC implements IrisService {
     public void onEnable() {
         J.a(() -> {
             String pack = IrisSettings.get().getGenerator().getDefaultWorldType();
-            File f = IrisPack.packsPack(pack);
 
-            if (!f.exists()) {
+            // Presence means a non-empty pack folder: an empty leftover folder must still
+            // trigger the install instead of shadowing it forever.
+            if (!PackDownloader.isPackPresent(getWorkspaceFolder(), pack)) {
                 if (PackDownloader.isDefaultOverworld(pack)) {
                     IrisLogging.info("Downloading Default Pack " + pack + " (beta release)");
                     IrisServices.get(StudioSVC.class).downloadDefaultOverworld(BukkitPlatform.console(), false);
@@ -203,8 +204,8 @@ public class StudioSVC implements IrisService {
                         }
                     }
                 }
-
-                IO.delete(downloaded);
+                // The downloaded pack stays in the packs workspace: deleting it here made the
+                // next startup see a missing pack and download it again.
             }
         }
 
@@ -231,6 +232,14 @@ public class StudioSVC implements IrisService {
     }
 
     public void downloadSearch(VolmitSender sender, String key, boolean forceOverwrite) {
+        // The default overworld always comes from the pinned release
+        // (PackDownloader.DEFAULT_OVERWORLD_RELEASE_URL), never from the listing,
+        // so every code path ships the same pack build.
+        if (PackDownloader.isDefaultOverworld(key)) {
+            downloadDefaultOverworld(sender, forceOverwrite);
+            return;
+        }
+
         try {
             String url = getListing(false).get(key);
 
@@ -244,7 +253,8 @@ public class StudioSVC implements IrisService {
             String[] nodes = url.split("\\Q/\\E");
             String repo = nodes.length == 1 ? "IrisDimensions/" + nodes[0] : nodes[0] + "/" + nodes[1];
             String branch = nodes.length > 2 ? nodes[2] : "stable";
-            download(sender, repo, branch, forceOverwrite, false);
+            String expectedKey = key.contains("/") ? null : key;
+            download(sender, repo, branch, forceOverwrite, false, expectedKey);
         } catch (Throwable e) {
             IrisLogging.reportError(e);
             e.printStackTrace();
@@ -253,6 +263,13 @@ public class StudioSVC implements IrisService {
     }
 
     public void downloadDefaultOverworld(VolmitSender sender, boolean forceOverwrite) {
+        // Same guard as download(): a present pack must not reach installDataPacks(true),
+        // which can trigger an automatic restart.
+        if (!forceOverwrite && PackDownloader.isPackPresent(getWorkspaceFolder(), PackDownloader.defaultOverworldPack())) {
+            sender.sendMessage(IrisLanguage.text(PackDownloadMessages.ALREADY_INSTALLED, MessageArgument.untrusted("key", PackDownloader.defaultOverworldPack())));
+            return;
+        }
+
         try {
             String key = PackDownloader.downloadDefaultOverworld(getWorkspaceFolder(), forceOverwrite, sender::sendMessage);
             if (key != null) {
@@ -280,7 +297,18 @@ public class StudioSVC implements IrisService {
     }
 
     public void download(VolmitSender sender, String repo, String branch, boolean forceOverwrite, boolean directUrl) throws JsonSyntaxException, IOException {
-        String key = PackDownloader.download(getWorkspaceFolder(), repo, branch, forceOverwrite, directUrl, sender::sendMessage);
+        download(sender, repo, branch, forceOverwrite, directUrl, null);
+    }
+
+    public void download(VolmitSender sender, String repo, String branch, boolean forceOverwrite, boolean directUrl, String expectedKey) throws JsonSyntaxException, IOException {
+        // Skip before PackDownloader so an already-present pack never reaches
+        // installDataPacks(true), which can trigger an automatic restart.
+        if (!forceOverwrite && PackDownloader.isPackPresent(getWorkspaceFolder(), expectedKey)) {
+            sender.sendMessage(IrisLanguage.text(PackDownloadMessages.ALREADY_INSTALLED, MessageArgument.untrusted("key", expectedKey)));
+            return;
+        }
+
+        String key = PackDownloader.download(getWorkspaceFolder(), repo, branch, forceOverwrite, directUrl, expectedKey, sender::sendMessage);
 
         if (key == null) {
             return;

core/src/main/java/art/arcane/iris/core/splash/IrisSplashComposer.java

@@ -22,12 +22,12 @@ public final class IrisSplashComposer {
                 prefix + style.title(" Iris, ") + style.subtitle("Dimension Engine ") + style.tag("[" + releaseTrain + "]"),
                 prefix + style.label(" Version: ") + style.value(version),
                 prefix + style.label(" By: ") + style.value("Volmit Software (Arcane Arts)"),
+                prefix + style.label(" Web: ") + style.value("VolmitSoftware.com"),
                 prefix + style.label(" Server: ") + style.value(serverLine),
                 prefix + style.label(" Java: ") + style.value(String.valueOf(javaVersion())) + style.label(" | Date: ") + style.value(startupDate()),
                 prefix + style.label(" Commit: ") + style.value(BuildConstants.COMMIT) + style.label("/") + style.value(BuildConstants.ENVIRONMENT),
                 "",
                 "",
-                "",
                 ""
         };
     }

core/src/main/java/art/arcane/iris/core/structure/FeatureImporter.java

@@ -19,6 +19,7 @@
 package art.arcane.iris.core.structure;
 
 import art.arcane.iris.core.IrisWorldStorage;
+import art.arcane.iris.core.WorldCreatorCompat;
 import art.arcane.iris.spi.IrisLogging;
 import art.arcane.iris.core.loader.IrisData;
 import art.arcane.iris.core.nms.INMS;
@@ -301,7 +302,7 @@ public final class FeatureImporter {
             if (existing != null) {
                 return existing;
             }
-            WorldCreator creator = WorldCreator.ofKey(IrisWorldStorage.keyFromName(SCRATCH_WORLD_NAME))
+            WorldCreator creator = WorldCreatorCompat.ofKey(IrisWorldStorage.keyFromName(SCRATCH_WORLD_NAME))
                     .environment(World.Environment.NORMAL)
                     .type(WorldType.FLAT)
                     .generateStructures(false);

core/src/main/java/art/arcane/iris/core/structure/VillageImporter.java

@@ -41,6 +41,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
@@ -49,9 +50,11 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 public final class VillageImporter {
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
+    private static final Set<String> PRINTED_FAILURE_SIGNATURES = ConcurrentHashMap.newKeySet();
 
     public record Result(boolean success, String message, int pools, int pieces, List<StructureLoss> losses) {
         public Result {
@@ -686,25 +689,62 @@ public final class VillageImporter {
         return opt;
     }
 
-    private static int readIntMember(Object value, String memberName) throws Exception {
+    static int readIntMember(Object value, String memberName) throws Exception {
         Class<?> type = value.getClass();
         while (type != null) {
             try {
                 Field field = type.getDeclaredField(memberName);
                 field.setAccessible(true);
-                return field.getInt(value);
+                return coerceInt(field.get(value), memberName, value);
             } catch (NoSuchFieldException ignored) {
                 type = type.getSuperclass();
             }
         }
         Method method = findMethod(value.getClass(), memberName);
-        if (method != null && Number.class.isAssignableFrom(boxedType(method.getReturnType()))) {
+        if (method != null) {
             method.setAccessible(true);
-            return ((Number) method.invoke(value)).intValue();
+            return coerceInt(method.invoke(value), memberName, value);
         }
         throw new NoSuchFieldException(memberName + " on " + value.getClass().getName());
     }
 
+    /**
+     * Members that are plain numbers on one server build are wrapper objects on another
+     * (JigsawStructure.maxDistanceFromCenter became a MaxDistance{horizontal, vertical} record).
+     * Numbers pass through; a wrapper contributes its horizontal component, else its largest
+     * integral component, so a distance bound is never under-read.
+     */
+    private static int coerceInt(Object member, String memberName, Object owner) throws Exception {
+        if (member instanceof Number n) {
+            return n.intValue();
+        }
+        if (member == null) {
+            throw new NoSuchFieldException(memberName + " on " + owner.getClass().getName() + " is null");
+        }
+        Method horizontal = findMethod(member.getClass(), "horizontal");
+        if (horizontal != null && Number.class.isAssignableFrom(boxedType(horizontal.getReturnType()))) {
+            horizontal.setAccessible(true);
+            return ((Number) horizontal.invoke(member)).intValue();
+        }
+        Integer widest = null;
+        for (Field component : member.getClass().getDeclaredFields()) {
+            if (Modifier.isStatic(component.getModifiers())
+                    || !Number.class.isAssignableFrom(boxedType(component.getType()))) {
+                continue;
+            }
+            component.setAccessible(true);
+            Object componentValue = component.get(member);
+            if (componentValue instanceof Number n && (widest == null || n.intValue() > widest)) {
+                widest = n.intValue();
+            }
+        }
+        if (widest != null) {
+            return widest;
+        }
+        throw new NoSuchFieldException(memberName + " on " + owner.getClass().getName()
+                + " is a " + member.getClass().getName() + " with no integral component");
+    }
+
     private static Class<?> boxedType(Class<?> type) {
         return type == int.class ? Integer.class : type;
     }
@@ -828,7 +868,28 @@ public final class VillageImporter {
 
     private static void reportFailure(Throwable failure) {
         IrisLogging.reportError(failure);
-        failure.printStackTrace();
+        if (shouldPrintFullTrace(failure)) {
+            failure.printStackTrace();
+        }
+    }
+
+    /**
+     * True the first time a failure signature is seen. A bulk import repeats the same failure once
+     * per registered structure, so printing every trace buries the boot log in hundreds of copies
+     * of one problem; the per-structure "[fail] key: message" line still reports each occurrence.
+     */
+    static boolean shouldPrintFullTrace(Throwable failure) {
+        if (failure == null) {
+            return false;
+        }
+        StackTraceElement[] trace = failure.getStackTrace();
+        String signature = failure.getClass().getName() + '|' + failure.getMessage()
+                + '|' + (trace.length == 0 ? "" : trace[0].toString());
+        return PRINTED_FAILURE_SIGNATURES.add(signature);
+    }
+
+    static void resetFailureLogState() {
+        PRINTED_FAILURE_SIGNATURES.clear();
     }
 
     private static void reportWriteFailure(StructureWriteResult result) {

core/src/main/java/art/arcane/iris/core/tools/IrisCreator.java

@@ -27,6 +27,7 @@ import art.arcane.iris.platform.bukkit.BukkitPlatform;
 import art.arcane.iris.core.link.MultiverseCoreLink;
 import art.arcane.iris.core.IrisRuntimeSchedulerMode;
 import art.arcane.iris.core.IrisWorldStorage;
+import art.arcane.iris.core.WorldCreatorCompat;
 import art.arcane.iris.core.IrisWorlds;
 import art.arcane.iris.core.IrisSettings;
 import art.arcane.iris.core.ServerConfigurator;
@@ -204,7 +205,7 @@ public class IrisCreator {
                 .studio(studio)
                 .create();
         if (!studio()) {
-            IrisWorlds.get().put(wc.key().toString(), dimension());
+            IrisWorlds.get().put(WorldCreatorCompat.keyOf(wc).toString(), dimension());
         }
         ServerConfigurator.installDataPacksIfChanged(!studio());
         IrisLogging.debug("[Studio timing]   create.packPrep + datapacks = " + (System.currentTimeMillis() - createStart) + "ms (cumulative in create)");

core/src/main/java/art/arcane/iris/core/tools/IrisWorldCreator.java

@@ -19,6 +19,7 @@
 package art.arcane.iris.core.tools;
 
 import art.arcane.iris.core.IrisWorldStorage;
+import art.arcane.iris.core.WorldCreatorCompat;
 import art.arcane.iris.core.loader.IrisData;
 import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.engine.object.IrisWorld;
@@ -92,7 +93,7 @@ public class IrisWorldCreator {
                 new File(w.worldFolder(), "iris/pack"), dimensionName);
 
 
-        return WorldCreator.ofKey(worldKey)
+        return WorldCreatorCompat.ofKey(worldKey)
                 .environment(environment)
                 .generateStructures(true)
                 .generator(g).seed(seed);

core/src/main/java/art/arcane/iris/engine/framework/NativeStructureGenerationPolicy.java

@@ -39,6 +39,13 @@ public final class NativeStructureGenerationPolicy {
                 "Dimension importedStructures must not be null");
         IrisNativeStructureDecision decision = control.resolve(structureKey, undergroundStep);
         if (!decision.generate()) {
+            // A disabled key with an active Iris placement is the "blanket-disable, re-place
+            // explicitly" pattern: the placement planner ignores the disable list, so generation
+            // places it — report REPLACED_BY_IRIS so find/goto/verify locate the placement.
+            if (decision.status() == NativeStructureGenerationStatus.DISABLED_BY_PACK
+                    && IrisStructureLocator.isPlaced(activeEngine, structureKey)) {
+                return decision.withStatus(NativeStructureGenerationStatus.REPLACED_BY_IRIS);
+            }
             return decision;
         }
         if (IrisStructureLocator.suppressesVanilla(activeEngine, structureKey)) {

core/src/main/java/art/arcane/iris/engine/object/IrisImportedStructureControl.java

@@ -39,7 +39,7 @@ import java.util.Objects;
 @Data
 public class IrisImportedStructureControl {
     @ArrayType(type = String.class, min = 1)
-    @RegistryListVanillaStructure
+    @RegistryListVanillaStructure(prefixes = true)
     @Desc("Structure keys to deny explicitly, e.g. 'minecraft:stronghold'. A namespace:path prefix also matches, so 'minecraft:village' disables every village variant and 'minecraft:ruined_portal' disables every ruined portal. Every key not matched here remains enabled.")
     private KList<String> disabled = new KList<>();
 

core/src/main/java/art/arcane/iris/engine/object/IrisVanillaStructureAdjustment.java

@@ -36,7 +36,7 @@ import lombok.experimental.Accessors;
 @Data
 public class IrisVanillaStructureAdjustment {
     @ArrayType(type = String.class, min = 1)
-    @RegistryListVanillaStructure
+    @RegistryListVanillaStructure(prefixes = true)
     @Desc("Structure keys this adjustment applies to, e.g. 'minecraft:stronghold'. A namespace:path prefix also matches, so 'minecraft:village' adjusts every village variant and 'minecraft:ruined_portal' adjusts every ruined portal. Empty matches nothing.")
     private KList<String> match = new KList<>();
 

core/src/main/java/art/arcane/iris/engine/object/annotations/RegistryListVanillaStructure.java

@@ -29,5 +29,12 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
 @Retention(RUNTIME)
 @Target({PARAMETER, TYPE, FIELD})
 public @interface RegistryListVanillaStructure {
-
+    /**
+     * When true the field accepts family/namespace prefixes in addition to exact registered keys
+     * (the {@code IrisImportedStructureControl.matchesKey} contract: "minecraft:village" matches
+     * every village variant, "nova_structures:" matches a whole namespace). The generated editor
+     * schema then validates entries against the registry enum OR a key/prefix pattern instead of
+     * rejecting anything that is not an exact registered key.
+     */
+    boolean prefixes() default false;
 }

core/src/main/resources/languages/de_DE.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Eine andere Dimension im Pack-Ordner verwendet bereits den Schlüssel {key}. Import fehlgeschlagen!",
     "iris.runtime.pack_download.pack_key_conflict": "Ein anderer Pack verwendet bereits den Schlüssel {key}. Import fehlgeschlagen!",
     "iris.runtime.pack_download.acquired": "{name} erfolgreich abgerufen.",
+    "iris.runtime.pack_download.already_installed": "Pack {key} ist bereits installiert, Download wird übersprungen.",
     "iris.runtime.pack_download.validation_failed": "Pack '{pack}' hat die Validierung nicht bestanden; Welt- und Studio-Erstellung werden verweigert. Gründe:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/es_ES.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Otra dimensión de la carpeta packs ya usa la clave {key}. ¡La importación falló!",
     "iris.runtime.pack_download.pack_key_conflict": "Otro pack usa la clave {key}. ¡La importación falló!",
     "iris.runtime.pack_download.acquired": "{name} se obtuvo correctamente.",
+    "iris.runtime.pack_download.already_installed": "El pack {key} ya está instalado, se omite la descarga.",
     "iris.runtime.pack_download.validation_failed": "El pack '{pack}' no superó la validación; se rechazará la creación de mundos y de Studio. Motivos:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/fi_FI.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Toinen ulottuvuus pakkauskansiossa jo käyttää avainta {key}.  Tuonti epäonnistui!",
     "iris.runtime.pack_download.pack_key_conflict": "Toinen pakkaus käyttää avainta {key}.  Tuonti epäonnistui!",
     "iris.runtime.pack_download.acquired": "Onnistunut hankinta {name}.",
+    "iris.runtime.pack_download.already_installed": "Pack {key} on jo asennettu, lataus ohitetaan.",
     "iris.runtime.pack_download.validation_failed": "Pakkaus{pack}' Epäonnistunut validointi; maailma ja Studio luominen hylätään.  Perusteet:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/fr_FR.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Une autre dimension du dossier packs utilise déjà la clé {key}. Échec de l'importation !",
     "iris.runtime.pack_download.pack_key_conflict": "Un autre pack utilise la clé {key}. Échec de l'importation !",
     "iris.runtime.pack_download.acquired": "{name} obtenu avec succès.",
+    "iris.runtime.pack_download.already_installed": "Le pack {key} est déjà installé, téléchargement ignoré.",
     "iris.runtime.pack_download.validation_failed": "Le pack '{pack}' a échoué à la validation ; la création de mondes et de Studio sera refusée. Raisons :",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/he_IL.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "מימד נוסף בתיקיה של הלהקה כבר משתמש המפתח {key}.  ייבוא נכשל!",
     "iris.runtime.pack_download.pack_key_conflict": "חבילה נוספת משתמשת במפתח {key}.  ייבוא נכשל!",
     "iris.runtime.pack_download.acquired": "נרכשה בהצלחה {name}.",
+    "iris.runtime.pack_download.already_installed": "החבילה {key} כבר מותקנת, ההורדה מדולגת.",
     "iris.runtime.pack_download.validation_failed": "Pack »{pack}\"התאימות הכושל; יצירת העולם והסטודיו לא תסרב.  סיבות:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/it_IT.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Un'altra dimensione nella cartella dei Pack usa già la chiave {key}. Importazione non riuscita!",
     "iris.runtime.pack_download.pack_key_conflict": "Un altro Pack usa già la chiave {key}. Importazione non riuscita!",
     "iris.runtime.pack_download.acquired": "{name} acquisito correttamente.",
+    "iris.runtime.pack_download.already_installed": "Il pack {key} è già installato, download saltato.",
     "iris.runtime.pack_download.validation_failed": "Il Pack '{pack}' non ha superato la convalida; la creazione di mondi e Studio verrà rifiutata. Motivi:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/ja-JP.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "packs フォルダー内の別のディメンションがキー {key} をすでに使用しています。インポートに失敗しました!",
     "iris.runtime.pack_download.pack_key_conflict": "別のパックがキー {key} を使用しています。インポートに失敗しました!",
     "iris.runtime.pack_download.acquired": "{name} を取得しました。",
+    "iris.runtime.pack_download.already_installed": "パック {key} は既にインストールされているため、ダウンロードをスキップします。",
     "iris.runtime.pack_download.validation_failed": "パック '{pack}' は検証に失敗しました。ワールドと Studio の作成を拒否します。理由:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/ko_KR.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "packs 폴더의 다른 차원이 이미 키 {key}을(를) 사용합니다. 가져오기에 실패했습니다!",
     "iris.runtime.pack_download.pack_key_conflict": "다른 팩이 키 {key}을(를) 사용합니다. 가져오기에 실패했습니다!",
     "iris.runtime.pack_download.acquired": "성공적으로 취득 {name}.",
+    "iris.runtime.pack_download.already_installed": "팩 {key}이(가) 이미 설치되어 있어 다운로드를 건너뜁니다.",
     "iris.runtime.pack_download.validation_failed": "팩 '{pack}' 유효성 검사; 세계 및 스튜디오 생성은 거부됩니다.  이유:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/lt_LT.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Kitas matmuo paketų aplanke jau naudoja raktą {key}.  Importuoti nepavyko!",
     "iris.runtime.pack_download.pack_key_conflict": "Kita pakuotė naudoja raktą {key}.  Importuoti nepavyko!",
     "iris.runtime.pack_download.acquired": "Sėkmingai įgyta {name}.",
+    "iris.runtime.pack_download.already_installed": "Paketas {key} jau įdiegtas, atsisiuntimas praleidžiamas.",
     "iris.runtime.pack_download.validation_failed": "Pakuotė \"{pack}\"nepavyko patvirtinimas; pasaulio ir Studio kūrimas bus atsisakyta.  Motyvai:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/nl_NL.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Een andere dimensie in de packs-map gebruikt al de sleutel {key}.  Importeren mislukt!",
     "iris.runtime.pack_download.pack_key_conflict": "Een ander pakje gebruikt de sleutel {key}.  Importeren mislukt!",
     "iris.runtime.pack_download.acquired": "Succesvol verworven {name}.",
+    "iris.runtime.pack_download.already_installed": "Pack {key} is al geïnstalleerd, download wordt overgeslagen.",
     "iris.runtime.pack_download.validation_failed": "Verpakking{pack}' mislukte validatie; wereld en Studio creatie zal worden geweigerd.  Motivering:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/pl_PL.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Inny wymiar w folderze pakietów już używa klucza {key}.  Import nie powiódł się!",
     "iris.runtime.pack_download.pack_key_conflict": "Inny pakiet używa klucza {key}.  Import nie powiódł się!",
     "iris.runtime.pack_download.acquired": "Udane nabycie {name}.",
+    "iris.runtime.pack_download.already_installed": "Pakiet {key} jest już zainstalowany, pomijanie pobierania.",
     "iris.runtime.pack_download.validation_failed": "Paczka \"{pack}\"nieudaną walidację; świat i tworzenie studia zostaną odrzucone.  Uzasadnienie:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/pt_PT.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Outra dimensão na pasta pacotes já está usando a chave {key}.  A importação falhou!",
     "iris.runtime.pack_download.pack_key_conflict": "Outro pacote está usando a chave {key}.  A importação falhou!",
     "iris.runtime.pack_download.acquired": "Adquirido com sucesso {name}.",
+    "iris.runtime.pack_download.already_installed": "O pack {key} já está instalado, download ignorado.",
     "iris.runtime.pack_download.validation_failed": "Embalar '{pack}' validação falhada; a criação de mundo e estúdio será recusada.  Motivos:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/ru_RU.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Еще одно измерение в папке пакетов уже использует ключ {key}.  Импорт провалился!",
     "iris.runtime.pack_download.pack_key_conflict": "Другой пакет использует ключ. {key}.  Импорт провалился!",
     "iris.runtime.pack_download.acquired": "Успешно приобретенный {name}.",
+    "iris.runtime.pack_download.already_installed": "Пак {key} уже установлен, загрузка пропущена.",
     "iris.runtime.pack_download.validation_failed": "Пакуй.{pack}Неудачная проверка; мир и создание студии будут отклонены.  Причины:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/tr_TR.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Paketlerdeki başka bir boyut zaten anahtarı kullanıyor {key}.  İthalat başarısız oldu!",
     "iris.runtime.pack_download.pack_key_conflict": "Başka bir paket anahtarı kullanıyor {key}.  İthalat başarısız oldu!",
     "iris.runtime.pack_download.acquired": "Başarılı bir şekilde satın alındı {name}.",
+    "iris.runtime.pack_download.already_installed": "{key} paketi zaten kurulu, indirme atlanıyor.",
     "iris.runtime.pack_download.validation_failed": "Pack \"{pack}“Başarısız doğrulama; dünya ve Stüdyo yaratımı reddedilecektir.  Sebepler:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/vi_VI.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "Một chiều không gian khác trong thư mục gói là đã sử dụng phím {key}.  Nhập thất bại!",
     "iris.runtime.pack_download.pack_key_conflict": "Name {key}.  Nhập thất bại!",
     "iris.runtime.pack_download.acquired": "Được thành công {name}.",
+    "iris.runtime.pack_download.already_installed": "Gói {key} đã được cài đặt, bỏ qua tải xuống.",
     "iris.runtime.pack_download.validation_failed": "Gói '{pack}'Đã thất bại trong việc xác nhận; thế giới và phòng thu sẽ bị từ chối.  Lý do:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/zh_CN.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "包文件夹中的另一个维度已经使用密钥 {key}.  导入失败 !",
     "iris.runtime.pack_download.pack_key_conflict": "另一个包是用钥匙 {key}.  导入失败 !",
     "iris.runtime.pack_download.acquired": "已成功获取 {name}.",
+    "iris.runtime.pack_download.already_installed": "包 {key} 已安装，跳过下载。",
     "iris.runtime.pack_download.validation_failed": "包{pack}' 验证失败; 世界和工作室的创建将被拒绝.  原因:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/main/resources/languages/zh_TW.json

@@ -1295,6 +1295,7 @@
     "iris.runtime.pack_download.dimension_key_conflict": "包資料夾中的另一個維度已經使用金鑰 {key}.  匯入失敗 !",
     "iris.runtime.pack_download.pack_key_conflict": "另一個包是用鑰匙 {key}.  匯入失敗 !",
     "iris.runtime.pack_download.acquired": "已成功獲取 {name}.",
+    "iris.runtime.pack_download.already_installed": "套件 {key} 已安裝，跳過下載。",
     "iris.runtime.pack_download.validation_failed": "包{pack}' 驗證失敗; 世界和工作室的建立將被拒絕.  原因:",
     "iris.runtime.pack_download.validation_reason": "  - {reason}",
     "iris.runtime.pack_download.validated_with_warnings": {

core/src/test/java/art/arcane/iris/core/IrisWorldStorageTest.java

@@ -6,6 +6,9 @@ import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
 import java.io.File;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.Properties;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
@@ -49,6 +52,37 @@ public class IrisWorldStorageTest {
         assertEquals("iris_world", IrisWorldStorage.logicalName(new NamespacedKey("iris", "iris_world"), "world"));
     }
 
+    @Test
+    public void readsLevelNameFromServerPropertiesFile() throws Exception {
+        File serverProperties = temporaryFolder.newFile("server.properties");
+        Files.write(serverProperties.toPath(), "level-name=psycho_world\nmotd=A Minecraft Server\n".getBytes(StandardCharsets.UTF_8));
+
+        assertEquals("psycho_world", IrisWorldStorage.levelNameFromProperties(serverProperties));
+    }
+
+    @Test
+    public void defaultsLevelNameWhenServerPropertiesMissing() {
+        File missing = new File(temporaryFolder.getRoot(), "missing/server.properties");
+
+        assertEquals("world", IrisWorldStorage.levelNameFromProperties(missing));
+    }
+
+    @Test
+    public void defaultsLevelNameWhenPropertyAbsentOrBlank() {
+        assertEquals("world", IrisWorldStorage.levelNameFromProperties(new Properties()));
+
+        Properties blank = new Properties();
+        blank.setProperty("level-name", "   ");
+        assertEquals("world", IrisWorldStorage.levelNameFromProperties(blank));
+    }
+
+    @Test
+    public void trimsLevelNameFromProperties() {
+        Properties padded = new Properties();
+        padded.setProperty("level-name", "  main_level  ");
+        assertEquals("main_level", IrisWorldStorage.levelNameFromProperties(padded));
+    }
+
     @Test
     public void rejectsKeysThatEscapeNamespaceStorage() throws Exception {
         File levelRoot = temporaryFolder.newFolder("world");

core/src/test/java/art/arcane/iris/core/WorldCreatorCompatTest.java

@@ -0,0 +1,40 @@
+package art.arcane.iris.core;
+
+import org.bukkit.NamespacedKey;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class WorldCreatorCompatTest {
+    @Test
+    public void keyedPathPreservesWorldKey() {
+        NamespacedKey key = new NamespacedKey("iris", "compat_world");
+
+        assertEquals(key, WorldCreatorCompat.ofKey(key).key());
+    }
+
+    @Test
+    public void fallbackNameDerivesLogicalNameFromKey() {
+        assertEquals("compat_world", WorldCreatorCompat.fallbackName(new NamespacedKey("iris", "compat_world"), "world"));
+        assertEquals("world", WorldCreatorCompat.fallbackName(NamespacedKey.minecraft("overworld"), "world"));
+        assertEquals("world_nether", WorldCreatorCompat.fallbackName(NamespacedKey.minecraft("the_nether"), "world"));
+        assertEquals("world_the_end", WorldCreatorCompat.fallbackName(NamespacedKey.minecraft("the_end"), "world"));
+    }
+
+    @Test
+    public void fallbackKeyRoundTripsCreatorName() {
+        assertEquals(new NamespacedKey("iris", "compat_world"), WorldCreatorCompat.fallbackKey("compat_world", "world"));
+        assertEquals(NamespacedKey.minecraft("overworld"), WorldCreatorCompat.fallbackKey("world", "world"));
+        assertEquals(NamespacedKey.minecraft("the_nether"), WorldCreatorCompat.fallbackKey("world_nether", "world"));
+    }
+
+    @Test
+    public void fallbackMappingIsStableAcrossRoundTrips() {
+        NamespacedKey key = new NamespacedKey("iris", "iris_world");
+
+        String name = WorldCreatorCompat.fallbackName(key, "world");
+
+        assertEquals(key, WorldCreatorCompat.fallbackKey(name, "world"));
+        assertEquals(name, WorldCreatorCompat.fallbackName(key, "world"));
+    }
+}

core/src/test/java/art/arcane/iris/core/pack/PackDownloaderTest.java

@@ -18,7 +18,15 @@
 
 package art.arcane.iris.core.pack;
 
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -26,6 +34,8 @@ import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 
 public class PackDownloaderTest {
+    @Rule
+    public TemporaryFolder temp = new TemporaryFolder();
     @Test
     public void resolvesDefaultOverworldBetaRelease() {
         assertEquals(
@@ -74,6 +84,55 @@ public class PackDownloaderTest {
         );
     }
 
+    @Test
+    public void isPackPresentRequiresNonEmptyFolder() throws IOException {
+        File packsFolder = temp.newFolder("packs");
+
+        assertFalse(PackDownloader.isPackPresent(packsFolder, "overworld"));
+        assertFalse(PackDownloader.isPackPresent(packsFolder, null));
+        assertFalse(PackDownloader.isPackPresent(packsFolder, ""));
+        assertFalse(PackDownloader.isPackPresent(null, "overworld"));
+
+        File pack = new File(packsFolder, "overworld");
+        assertTrue(pack.mkdirs());
+        assertFalse(PackDownloader.isPackPresent(packsFolder, "overworld"));
+
+        // A partial import (content but no dimension file) counts as absent so it can be replaced.
+        File biomes = new File(pack, "biomes");
+        assertTrue(biomes.mkdirs());
+        Files.writeString(new File(biomes, "plains.json").toPath(), "{}");
+        assertFalse(PackDownloader.isPackPresent(packsFolder, "overworld"));
+
+        File dimensions = new File(pack, "dimensions");
+        assertTrue(dimensions.mkdirs());
+        Files.writeString(new File(dimensions, "overworld.json").toPath(), "{}");
+        assertTrue(PackDownloader.isPackPresent(packsFolder, "overworld"));
+    }
+
+    @Test
+    public void downloadSkipsWhenExpectedPackAlreadyPresent() throws IOException {
+        File packsFolder = temp.newFolder("packs");
+        File dimensions = new File(packsFolder, "overworld/dimensions");
+        assertTrue(dimensions.mkdirs());
+        Files.writeString(new File(dimensions, "overworld.json").toPath(), "{}");
+
+        List<String> feedback = new ArrayList<>();
+        // The URL is unreachable on purpose: reaching the network would fail the download and
+        // return null, so a non-null key proves the presence check ran before any fetch.
+        String key = PackDownloader.download(
+                packsFolder,
+                "IrisDimensions/overworld",
+                "http://127.0.0.1:9/unreachable.zip",
+                false,
+                true,
+                "overworld",
+                feedback::add
+        );
+
+        assertEquals("overworld", key);
+        assertFalse(feedback.isEmpty());
+    }
+
     @Test
     public void rejectsUnsafeRepositoryAndReference() {
         assertThrows(IllegalArgumentException.class, () -> PackDownloader.resolveGithubArchiveUrl("IrisDimensions/overworld?raw=1", "master"));

core/src/test/java/art/arcane/iris/core/project/VanillaStructurePrefixSchemaTest.java

@@ -0,0 +1,68 @@
+package art.arcane.iris.core.project;
+
+import art.arcane.iris.engine.object.IrisImportedStructureControl;
+import art.arcane.iris.engine.object.IrisVanillaStructureAdjustment;
+import art.arcane.iris.engine.object.annotations.ArrayType;
+import art.arcane.iris.engine.object.annotations.Desc;
+import art.arcane.iris.engine.object.annotations.RegistryListVanillaStructure;
+import art.arcane.volmlib.util.collection.KList;
+import art.arcane.volmlib.util.json.JSONArray;
+import art.arcane.volmlib.util.json.JSONObject;
+import org.junit.Test;
+
+import java.util.regex.Pattern;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * importedStructures.disabled and adjustments[].match accept family/namespace PREFIXES
+ * ("minecraft:village", "nova_structures:") per IrisImportedStructureControl.matchesKey, so the
+ * generated editor schema must not reject them with a strict registered-key enum. Prefix-capable
+ * fields emit an anyOf of the registry enum plus a key/prefix pattern; exact-key fields (e.g.
+ * nativeStructures[].structure) keep the strict enum.
+ */
+public class VanillaStructurePrefixSchemaTest {
+    @Test
+    public void prefixCapableFieldsDeclareThePrefixAnnotation() throws NoSuchFieldException {
+        assertTrue(IrisImportedStructureControl.class.getDeclaredField("disabled")
+                .getAnnotation(RegistryListVanillaStructure.class).prefixes());
+        assertTrue(IrisVanillaStructureAdjustment.class.getDeclaredField("match")
+                .getAnnotation(RegistryListVanillaStructure.class).prefixes());
+    }
+
+    @Test
+    public void prefixListSchemaAcceptsFamilyAndNamespacePrefixes() {
+        JSONObject schema = new SchemaBuilder(PrefixModel.class, null).construct();
+        JSONObject items = schema.getJSONObject("properties").getJSONObject("disabled")
+                .getJSONObject("items");
+        String definitionKey = items.getString("$ref").substring("#/definitions/".length());
+        JSONArray anyOf = schema.getJSONObject("definitions").getJSONObject(definitionKey)
+                .getJSONArray("anyOf");
+
+        String pattern = null;
+        for (int i = 0; i < anyOf.length(); i++) {
+            JSONObject branch = anyOf.getJSONObject(i);
+            if (branch.has("pattern")) {
+                pattern = branch.getString("pattern");
+            }
+        }
+        assertTrue("anyOf must contain a pattern branch for prefixes", pattern != null);
+
+        Pattern compiled = Pattern.compile(pattern);
+        assertTrue(compiled.matcher("minecraft:village").matches());
+        assertTrue(compiled.matcher("minecraft:pillager_outpost").matches());
+        assertTrue(compiled.matcher("nova_structures:").matches());
+        assertTrue(compiled.matcher("towns_and_towers:exclusives/village_piglin").matches());
+        assertFalse(compiled.matcher("village").matches());
+        assertFalse(compiled.matcher("Nova Structures:tavern").matches());
+    }
+
+    @Desc("Schema model for prefix-capable vanilla structure lists.")
+    public static class PrefixModel {
+        @RegistryListVanillaStructure(prefixes = true)
+        @ArrayType(type = String.class, min = 1)
+        @Desc("Prefix-capable deny list.")
+        private KList<String> disabled = new KList<>();
+    }
+}

core/src/test/java/art/arcane/iris/core/splash/IrisSplashComposerTest.java

@@ -14,4 +14,14 @@ public class IrisSplashComposerTest {
         assertEquals(" Version: 4.0.0-26.2", info[2]);
         assertFalse(String.join("\n", info).contains("RC.1.1.6"));
     }
+
+    @Test
+    public void composeInfoShowsWebsiteAndKeepsSplashHeight() {
+        String[] info = IrisSplashComposer.composeInfo("4.0.0-26.2", "Paper 26.2", IrisSplashComposer.InfoStyle.PLAIN);
+
+        assertEquals(11, info.length);
+        assertEquals(" By: Volmit Software (Arcane Arts)", info[3]);
+        assertEquals(" Web: VolmitSoftware.com", info[4]);
+        assertEquals(" Server: Paper 26.2", info[5]);
+    }
 }

core/src/test/java/art/arcane/iris/core/structure/VillageImporterFailureLogTest.java

@@ -0,0 +1,48 @@
+package art.arcane.iris.core.structure;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * A bulk import walks every registered datapack structure, so one broken server-side assumption
+ * fails hundreds of times in a row from the same throw site. Printing a full stack trace per
+ * structure buried a Leaf 26.2 boot under ~4,700 identical lines. The first occurrence of a failure
+ * signature prints in full; repeats are counted by the per-structure "[fail] key: message" line
+ * instead of re-printing.
+ */
+public class VillageImporterFailureLogTest {
+    /** One throw site, mirroring a repeated in-loop failure (same class, message, and top frame). */
+    private static Throwable raise(boolean illegalArgument, String message) {
+        return illegalArgument ? new IllegalArgumentException(message) : new IllegalStateException(message);
+    }
+
+    @Test
+    public void repeatedIdenticalFailuresPrintOnce() {
+        VillageImporter.resetFailureLogState();
+
+        assertTrue(VillageImporter.shouldPrintFullTrace(
+                raise(true, "illegal data type conversion to int")));
+        for (int i = 0; i < 200; i++) {
+            assertFalse(VillageImporter.shouldPrintFullTrace(
+                    raise(true, "illegal data type conversion to int")));
+        }
+    }
+
+    @Test
+    public void distinctFailuresEachPrintOnce() {
+        VillageImporter.resetFailureLogState();
+
+        assertTrue(VillageImporter.shouldPrintFullTrace(raise(true, "a")));
+        assertTrue(VillageImporter.shouldPrintFullTrace(raise(false, "a")));
+        assertTrue(VillageImporter.shouldPrintFullTrace(raise(true, "b")));
+        assertFalse(VillageImporter.shouldPrintFullTrace(raise(true, "b")));
+    }
+
+    @Test
+    public void nullFailureIsNotPrinted() {
+        VillageImporter.resetFailureLogState();
+        assertFalse(VillageImporter.shouldPrintFullTrace(null));
+    }
+}

core/src/test/java/art/arcane/iris/core/structure/VillageImporterMaxDistanceReadTest.java

@@ -0,0 +1,44 @@
+package art.arcane.iris.core.structure;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * JigsawStructure.maxDistanceFromCenter is a plain int on some server builds and a
+ * JigsawStructure$MaxDistance record ({int horizontal, int vertical}) on others (e.g. Leaf
+ * 26.2-33). The reflective member reader must handle both — the wrapper shape previously threw
+ * IllegalArgumentException from Field.getInt, failing the jigsaw import of every datapack
+ * structure ("Failed to read jigsaw structure graph").
+ */
+public class VillageImporterMaxDistanceReadTest {
+    private static final class IntShape {
+        private final int maxDistanceFromCenter = 80;
+    }
+
+    private record MaxDistance(int horizontal, int vertical) {
+    }
+
+    private static final class WrapperShape {
+        private final MaxDistance maxDistanceFromCenter = new MaxDistance(96, 48);
+    }
+
+    private static final class BoxedShape {
+        private final Integer maxDistanceFromCenter = 64;
+    }
+
+    @Test
+    public void readsPlainIntField() throws Exception {
+        assertEquals(80, VillageImporter.readIntMember(new IntShape(), "maxDistanceFromCenter"));
+    }
+
+    @Test
+    public void readsLargestIntComponentFromWrapperRecord() throws Exception {
+        assertEquals(96, VillageImporter.readIntMember(new WrapperShape(), "maxDistanceFromCenter"));
+    }
+
+    @Test
+    public void readsBoxedNumberField() throws Exception {
+        assertEquals(64, VillageImporter.readIntMember(new BoxedShape(), "maxDistanceFromCenter"));
+    }
+}

core/src/test/java/art/arcane/iris/engine/framework/NativeStructureGenerationPolicyTest.java

@@ -1,9 +1,20 @@
 package art.arcane.iris.engine.framework;
 
+import art.arcane.iris.core.loader.IrisData;
+import art.arcane.iris.engine.object.IrisDimension;
+import art.arcane.iris.engine.object.IrisImportedStructureControl;
+import art.arcane.iris.engine.object.IrisNativeStructure;
+import art.arcane.iris.engine.object.IrisNativeStructureDecision;
+import art.arcane.iris.engine.object.IrisRegion;
+import art.arcane.iris.engine.object.IrisStructurePlacement;
 import art.arcane.iris.engine.object.NativeStructureGenerationStatus;
+import art.arcane.volmlib.util.collection.KList;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 public class NativeStructureGenerationPolicyTest {
     @Test
@@ -17,4 +28,53 @@ public class NativeStructureGenerationPolicyTest {
                 NativeStructureGenerationPolicy.generationStatusMessage(
                         "minecraft:ancient_city", NativeStructureGenerationStatus.REPLACED_BY_IRIS));
     }
+
+    /**
+     * The "blanket-disable a namespace, re-place chosen structures via nativeStructures placements"
+     * pattern: generation honors the placement (the planner never consults the disable list), so the
+     * policy must report those keys as REPLACED_BY_IRIS — making /iris find|goto and
+     * /iris structure verify locate the placement instead of claiming the key is disabled.
+     */
+    @Test
+    public void disabledKeyWithActivePlacementResolvesAsReplacedByIris() {
+        Engine engine = engineWithDisabledNamespaceAndRegionPlacement("nova_structures:tavern_oak");
+
+        assertEquals(NativeStructureGenerationStatus.REPLACED_BY_IRIS,
+                NativeStructureGenerationPolicy.resolve(engine, "nova_structures:tavern_oak", false).status());
+    }
+
+    @Test
+    public void disabledKeyWithoutPlacementStaysDisabled() {
+        Engine engine = engineWithDisabledNamespaceAndRegionPlacement("nova_structures:tavern_oak");
+
+        IrisNativeStructureDecision decision =
+                NativeStructureGenerationPolicy.resolve(engine, "nova_structures:witch_villa", false);
+        assertEquals(NativeStructureGenerationStatus.DISABLED_BY_PACK, decision.status());
+        assertFalse(decision.generate());
+    }
+
+    private Engine engineWithDisabledNamespaceAndRegionPlacement(String placedKey) {
+        IrisData data = mock(IrisData.class);
+        Engine engine = mock(Engine.class);
+        IrisDimension dimension = mock(IrisDimension.class);
+        IrisImportedStructureControl control = new IrisImportedStructureControl();
+        control.getDisabled().add("nova_structures:");
+
+        IrisStructurePlacement placement = new IrisStructurePlacement();
+        placement.getNativeStructures().add(new IrisNativeStructure().setStructure(placedKey));
+        IrisRegion region = mock(IrisRegion.class);
+        KList<IrisStructurePlacement> regionPlacements = new KList<>();
+        regionPlacements.add(placement);
+        when(region.getStructures()).thenReturn(regionPlacements);
+        KList<IrisRegion> regions = new KList<>();
+        regions.add(region);
+
+        when(engine.getData()).thenReturn(data);
+        when(engine.getDimension()).thenReturn(dimension);
+        when(dimension.getImportedStructures()).thenReturn(control);
+        when(dimension.getStructures()).thenReturn(new KList<>());
+        when(dimension.getAllRegions(engine)).thenReturn(regions);
+        when(dimension.getReachableBiomes(engine)).thenReturn(new KList<>());
+        return engine;
+    }
 }