Fix

src/main/java/com/volmit/iris/gen/ParallaxTerrainProvider.java

@@ -56,6 +56,7 @@ public abstract class ParallaxTerrainProvider extends TopographicTerrainProvider
 		setSliverCache(new KMap<>());
 		setSliverBuffer(sliverBuffer);
 		setMasterLock(new MasterLock());
+		getMasterLock().disable();
 	}
 
 	public void onInit(RNG rng)
@@ -157,7 +158,7 @@ public abstract class ParallaxTerrainProvider extends TopographicTerrainProvider
 
 		return new AtomicSliverMap();
 	}
-	
+
 	@Override
 	public List<BlockPopulator> getPopulators()
 	{

src/main/java/com/volmit/iris/gen/atomics/AtomicWorldData.java

@@ -8,6 +8,7 @@ import java.io.IOException;
 import com.volmit.iris.Iris;
 import com.volmit.iris.gen.scaffold.TerrainTarget;
 import com.volmit.iris.util.ChunkPosition;
+import com.volmit.iris.util.IrisLock;
 import com.volmit.iris.util.KList;
 import com.volmit.iris.util.KMap;
 import com.volmit.iris.util.M;
@@ -21,6 +22,7 @@ public class AtomicWorldData
 	private KMap<ChunkPosition, Long> lastChunk;
 	private KList<ChunkPosition> unloadRegions;
 	private KList<ChunkPosition> unloadChunks;
+	private IrisLock lock = new IrisLock("ULLock");
 	private long last = M.ms();
 
 	public AtomicWorldData(TerrainTarget world)
@@ -263,8 +265,10 @@ public class AtomicWorldData
 
 	public void clean(int j)
 	{
+		lock.lock();
 		if(M.ms() - last < getUnloadBatchSpeed())
 		{
+			lock.unlock();
 			return;
 		}
 
@@ -331,6 +335,7 @@ public class AtomicWorldData
 		}
 
 		unloadChunks.clear();
+		lock.unlock();
 	}
 
 	private int getUnloadBatchSize()

src/main/java/com/volmit/iris/gen/atomics/MasterLock.java

@@ -7,9 +7,11 @@ public class MasterLock
 {
 	private KMap<String, IrisLock> locks;
 	private IrisLock lock;
+	private boolean enabled;
 
 	public MasterLock()
 	{
+		enabled = true;
 		locks = new KMap<>();
 		lock = new IrisLock("MasterLock");
 	}
@@ -19,8 +21,18 @@ public class MasterLock
 		locks.clear();
 	}
 
+	public void disable()
+	{
+		enabled = false;
+	}
+
 	public void lock(String key)
 	{
+		if(!enabled)
+		{
+			return;
+		}
+
 		lock.lock();
 		if(!locks.containsKey(key))
 		{
@@ -34,6 +46,11 @@ public class MasterLock
 
 	public void unlock(String key)
 	{
+		if(!enabled)
+		{
+			return;
+		}
+		
 		lock.lock();
 		if(!locks.containsKey(key))
 		{

src/main/java/com/volmit/iris/gen/provisions/ProvisionBukkit.java

@@ -2,6 +2,7 @@ package com.volmit.iris.gen.provisions;
 
 import java.util.List;
 import java.util.Random;
+import java.util.function.Consumer;
 
 import org.bukkit.Location;
 import org.bukkit.World;
@@ -13,7 +14,6 @@ import com.volmit.iris.gen.scaffold.Provisioned;
 import com.volmit.iris.gen.scaffold.TerrainChunk;
 import com.volmit.iris.gen.scaffold.TerrainProvider;
 import com.volmit.iris.util.ChunkPosition;
-import com.volmit.iris.util.J;
 import com.volmit.iris.util.KMap;
 import com.volmit.iris.util.RNG;
 
@@ -41,7 +41,7 @@ public class ProvisionBukkit extends ChunkGenerator implements Provisioned
 		world.unloadChunkRequest(x, z);
 	}
 
-	public void generateAsync(World world, int x, int z)
+	public void generateAsync(World world, int x, int z, Consumer<Boolean> onDone)
 	{
 		ChunkPosition c = new ChunkPosition(x, z);
 
@@ -50,7 +50,12 @@ public class ProvisionBukkit extends ChunkGenerator implements Provisioned
 			TerrainChunk snapshot = TerrainChunk.create(world);
 			snapshot.setRaw(generateChunkData(world, getRNG(world, x, z), x, z, snapshot));
 			precache.put(c, snapshot);
-			J.s(() -> generate(world, x, z));
+			onDone.accept(true);
+		}
+
+		else
+		{
+			onDone.accept(false);
 		}
 	}
 
@@ -70,7 +75,7 @@ public class ProvisionBukkit extends ChunkGenerator implements Provisioned
 			{
 				TerrainChunk snapshot = precache.remove(c);
 				snapshot.inject(biome);
-				return snapshot;
+				return snapshot.getRaw();
 			}
 		}