[#SPIGOT-6908] "Entity {...} is not in the region" server crash loop

My server has some chunks that will crash the server when they load. This seems to be due to an entity that is outside of the region with a very high Y-value.

java.lang.IllegalStateException: Entity EntityWitherSkull['Wither Skull'/811, l='ServerLevel[world]', x=-4464.26, y=2560.84, z=-2255.58] is not in the region	at com.google.common.base.Preconditions.checkState(Preconditions.java:590) ~[guava-31.0.1-jre.jar:?]	at org.bukkit.craftbukkit.v1_18_R1.generator.CraftLimitedRegion.saveEntities(CraftLimitedRegion.java:98) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]

I can not reproduce this problem from scratch, this server is very old so it's possible that this entity has been there since prior versions of MC/Spigot that did not have this check?

I also can't identify the faulty region files, but if you do need a repro case and can help me map those x/z coordinates to a region file, I'm happy to attach it!

It seems odd I have never seen this before, but since updating to 1.18 my server crashes every few days, when certain players try to log in and these broken chunks load. I looked through git history and the check doesn't seem that new, so I'm confused as to what's going on- something to do with the world height change, I'm guessing?

if (entity.isAlive()) {
    // check if entity is still in region or if it got teleported outside it
    Preconditions.checkState(region.contains(entity.getX(), entity.getY(), entity.getZ()), "Entity %s is not in the region", entity);
    access.addFreshEntity(entity);
}

Would it be possible to skip saving the entity in this case, rather than hard-crashing the server?

Full stack trace - most of this will repeat several times before the server shuts down.

[17:15:54] [Server thread/FATAL]: Error executing task on Chunk source main thread executor for minecraft:overworldnet.minecraft.ReportedException: Exception generating new chunk	at net.minecraft.server.level.PlayerChunkMap.lambda$29(PlayerChunkMap.java:653) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.util.thread.IAsyncTaskHandler.c(SourceFile:151) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.level.ChunkProviderServer$b.c(ChunkProviderServer.java:634) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.util.thread.IAsyncTaskHandler.y(SourceFile:125) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.level.ChunkProviderServer$b.y(ChunkProviderServer.java:645) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.util.thread.IAsyncTaskHandler.c(SourceFile:134) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.level.ChunkProviderServer.a(ChunkProviderServer.java:163) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.World.a(World.java:283) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.IWorldReader.a(SourceFile:140) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.World.d(World.java:277) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.World.l(World.java:272) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.World.b_(World.java:609) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.entity.Entity.l(Entity.java:1325) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.entity.Entity.an(Entity.java:573) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.entity.EntityLiving.an(EntityLiving.java:388) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.entity.Entity.k(Entity.java:539) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.entity.EntityLiving.k(EntityLiving.java:2766) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.entity.player.EntityHuman.k(EntityHuman.java:260) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.level.EntityPlayer.l(EntityPlayer.java:621) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.network.PlayerConnection.b(PlayerConnection.java:299) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.network.NetworkManager.a(NetworkManager.java:250) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.network.ServerConnection.c(ServerConnection.java:172) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1322) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.dedicated.DedicatedServer.b(DedicatedServer.java:428) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:1206) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:1034) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:304) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at java.lang.Thread.run(Thread.java:833) [?:?]Caused by: java.lang.IllegalStateException: Entity EntityWitherSkull['Wither Skull'/811, l='ServerLevel[world]', x=-4464.26, y=2560.84, z=-2255.58] is not in the region	at com.google.common.base.Preconditions.checkState(Preconditions.java:590) ~[guava-31.0.1-jre.jar:?]	at org.bukkit.craftbukkit.v1_18_R1.generator.CraftLimitedRegion.saveEntities(CraftLimitedRegion.java:98) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:388) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.chunk.ChunkGenerator.a(ChunkGenerator.java:369) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.chunk.ChunkStatus.lambda$11(ChunkStatus.java:148) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.world.level.chunk.ChunkStatus.a(ChunkStatus.java:273) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.server.level.PlayerChunkMap.lambda$26(PlayerChunkMap.java:638) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at com.mojang.datafixers.util.Either$Left.map(Either.java:38) ~[datafixerupper-4.0.26.jar:?]	at net.minecraft.server.level.PlayerChunkMap.lambda$25(PlayerChunkMap.java:636) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150) ~[?:?]	at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482) ~[?:?]	at net.minecraft.server.level.ChunkTaskQueueSorter.b(SourceFile:58) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.util.thread.ThreadedMailbox.g(SourceFile:91) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.util.thread.ThreadedMailbox.a(SourceFile:146) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at net.minecraft.util.thread.ThreadedMailbox.run(SourceFile:102) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3408-Spigot-f4ff00f-74a5cc8]	at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1395) ~[?:?]	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373) ~[?:?]	at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182) ~[?:?]	at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655) ~[?:?]	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622) ~[?:?]	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165) ~[?:?][1

I am not the only one having this issue, but it must be rare as I can't find anything here or via Google.

[SPIGOT-6908] "Entity {...} is not in the region" server crash loop Created: 22/Jan/22 Updated: 22/Jan/22 Resolved: 22/Jan/22
Status:	Resolved
Project:	Spigot
Component/s:	None
Affects Version/s:	None
Fix Version/s:	None

[SPIGOT-6908] "Entity {...} is not in the region" server crash loop Created: 22/Jan/22 Updated: 22/Jan/22 Resolved: 22/Jan/22