diff --git a/Spigot-Server-Patches/Async-Chunk-Loading-and-Generation.patch b/Spigot-Server-Patches/Async-Chunk-Loading-and-Generation.patch
index 312df2dbe3..725ac93b79 100644
--- a/Spigot-Server-Patches/Async-Chunk-Loading-and-Generation.patch
+++ b/Spigot-Server-Patches/Async-Chunk-Loading-and-Generation.patch
@@ -713,7 +713,7 @@ index 186cfda7e..781e06877 100644
      }
  
 diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
-index d938eb374..51df075b4 100644
+index d938eb374..7734712af 100644
 --- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
 +++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
 @@ -0,0 +0,0 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
@@ -725,6 +725,21 @@ index d938eb374..51df075b4 100644
              if (cps.isLoaded(x, z)) {
                  return true;
              }
+@@ -0,0 +0,0 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
+         }
+     }
+ 
++    private final Object legacyStructureLock = new Object(); // Paper
++    public void getPersistentStructureLegacy(DimensionManager dimensionmanager, @Nullable PersistentCollection persistentcollection) { this.a(dimensionmanager, persistentcollection); } // Paper
+     public void a(DimensionManager dimensionmanager, @Nullable PersistentCollection persistentcollection) {
+         if (this.e == null) {
++        synchronized (legacyStructureLock){ if (this.e == null) { // Paper
+             this.e = PersistentStructureLegacy.a(dimensionmanager, persistentcollection);
+-        }
++        } } } // Paper
+ 
+     }
+ 
 @@ -0,0 +0,0 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
                      }
                  };
@@ -947,13 +962,14 @@ index be555f82d..3e81ebdb8 100644
          this.aJ = Sets.newHashSet();
          this.aL = new double[] { 0.0D, 0.0D, 0.0D};
 diff --git a/src/main/java/net/minecraft/server/IChunkLoader.java b/src/main/java/net/minecraft/server/IChunkLoader.java
-index 4698ee99f..dfb45cc4e 100644
+index 4698ee99f..431f4ab18 100644
 --- a/src/main/java/net/minecraft/server/IChunkLoader.java
 +++ b/src/main/java/net/minecraft/server/IChunkLoader.java
 @@ -0,0 +0,0 @@ import javax.annotation.Nullable;
  
  public interface IChunkLoader {
  
++    void getPersistentStructureLegacy(DimensionManager dimensionmanager, @Nullable PersistentCollection persistentcollection); // Paper
 +    void loadEntities(NBTTagCompound nbttagcompound, Chunk chunk); // Paper - Async Chunks
 +    Object[] loadChunk(GeneratorAccess generatoraccess, int i, int j, Consumer<Chunk> consumer) throws IOException; // Paper - Async Chunks
      @Nullable
@@ -2056,7 +2072,7 @@ index 284e96710..8b08efe1f 100644
      }
  
 diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
-index a7302b39c..739fbecac 100644
+index 4c971ddfb..1c66c833b 100644
 --- a/src/main/java/net/minecraft/server/World.java
 +++ b/src/main/java/net/minecraft/server/World.java
 @@ -0,0 +0,0 @@ import org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason;
@@ -2306,9 +2322,17 @@ index 69d8a25bd..d0eaa9e9f 100644
                  }
              }
 diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
-index 0ff3fe03d..9b5509dce 100644
+index 0ff3fe03d..e71a40580 100644
 --- a/src/main/java/net/minecraft/server/WorldServer.java
 +++ b/src/main/java/net/minecraft/server/WorldServer.java
+@@ -0,0 +0,0 @@ public class WorldServer extends World implements IAsyncTaskHandler {
+         this.P();
+         this.Q();
+         this.getWorldBorder().a(minecraftserver.au());
++        MCUtil.scheduleAsyncTask(() -> this.getChunkProvider().chunkLoader.getPersistentStructureLegacy(dimensionmanager, worldMaps)); // Paper
+     }
+ 
+     public WorldServer i_() {
 @@ -0,0 +0,0 @@ public class WorldServer extends World implements IAsyncTaskHandler {
              gen = new org.bukkit.craftbukkit.generator.NormalChunkGenerator(this, this.getSeed());
          }
@@ -2347,7 +2371,7 @@ index fac42f8e5..59b1628e5 100644
              }
          }
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index 95fe3a91b..b5a87cfaf 100644
+index 0e4455d66..eacecccfd 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {
@@ -2385,7 +2409,7 @@ index 95fe3a91b..b5a87cfaf 100644
                      if (isChunkLoaded(chunkCoordX + x, chunkCoordZ + z)) {
                          unloadChunk(chunkCoordX + x, chunkCoordZ + z);
 diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
-index 054ebc82b..2e0b4de83 100644
+index 68e30185a..7905420ca 100644
 --- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
 +++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
 @@ -0,0 +0,0 @@ public class CraftEventFactory {
diff --git a/Spigot-Server-Patches/Entity-getEntitySpawnReason.patch b/Spigot-Server-Patches/Entity-getEntitySpawnReason.patch
index cc45b7a2ff..2a5a27e05a 100644
--- a/Spigot-Server-Patches/Entity-getEntitySpawnReason.patch
+++ b/Spigot-Server-Patches/Entity-getEntitySpawnReason.patch
@@ -10,7 +10,7 @@ persistenting Living Entity, SPAWNER for spawners,
 or DEFAULT since data was not stored.
 
 diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
-index 51df075b4..53ae5d509 100644
+index 7734712af..dce52ac0f 100644
 --- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
 +++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
 @@ -0,0 +0,0 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
@@ -98,7 +98,7 @@ index b1630137e..df416e3b5 100644
              if (entity != null) {
                  UUID uuid = nbttagcompound1.a("Attach");
 diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
-index 0624848cc..9faed9303 100644
+index 5b4bce464..2d436feab 100644
 --- a/src/main/java/net/minecraft/server/World.java
 +++ b/src/main/java/net/minecraft/server/World.java
 @@ -0,0 +0,0 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
diff --git a/Spigot-Server-Patches/Limit-lightning-strike-effect-distance.patch b/Spigot-Server-Patches/Limit-lightning-strike-effect-distance.patch
index 3f45e0450a..6318b1e5b1 100644
--- a/Spigot-Server-Patches/Limit-lightning-strike-effect-distance.patch
+++ b/Spigot-Server-Patches/Limit-lightning-strike-effect-distance.patch
@@ -5,7 +5,7 @@ Subject: [PATCH] Limit lightning strike effect distance
 
 
 diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
-index 0b54b7d78..d723868fc 100644
+index e04204055..30985cdfc 100644
 --- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 +++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 @@ -0,0 +0,0 @@ public class PaperWorldConfig {
@@ -69,7 +69,7 @@ index 7781babf5..50f620009 100644
  
          --this.lifeTicks;
 diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
-index 9b5509dce..409b50744 100644
+index e71a40580..53e7834cc 100644
 --- a/src/main/java/net/minecraft/server/WorldServer.java
 +++ b/src/main/java/net/minecraft/server/WorldServer.java
 @@ -0,0 +0,0 @@ public class WorldServer extends World implements IAsyncTaskHandler {
diff --git a/Spigot-Server-Patches/Use-EntityTypes-for-living-entities.patch b/Spigot-Server-Patches/Use-EntityTypes-for-living-entities.patch
index 60856f2c3c..6bfc2730dd 100644
--- a/Spigot-Server-Patches/Use-EntityTypes-for-living-entities.patch
+++ b/Spigot-Server-Patches/Use-EntityTypes-for-living-entities.patch
@@ -639,7 +639,7 @@ index 11010d8e1..4eb746ebb 100644
                  entityvindicator.setPositionRotation(blockposition, 0.0F, 0.0F);
                  entityvindicator.prepare(generatoraccess.getDamageScaler(new BlockPosition(entityvindicator)), (GroupDataEntity) null, (NBTTagCompound) null);
 diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
-index 409b50744..a4fc1e5e2 100644
+index 53e7834cc..5c2421ac3 100644
 --- a/src/main/java/net/minecraft/server/WorldServer.java
 +++ b/src/main/java/net/minecraft/server/WorldServer.java
 @@ -0,0 +0,0 @@ public class WorldServer extends World implements IAsyncTaskHandler {
@@ -652,7 +652,7 @@ index 409b50744..a4fc1e5e2 100644
                              entityhorseskeleton.s(true);
                              entityhorseskeleton.setAgeRaw(0);
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
-index e33135ada..6ed7c9355 100644
+index 7c0a53053..40ee34675 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {