Does not work with async-chunks

[Malfrador]

Describe the issue When using Paper with async-chunks enabled, the server crashes when loading chunks in a Slime-World. RuntimeException: Error while adding chunk to cache. Too many neighbors Spigot version Paper (1.13.2) Plugin version 2.2.0 How to reproduce

(0). Enable async chunks in paper.yml

1. Import a vanilla world
2. Load the world
3. Fly around a bit
4. Server crashes

Crash reports (if available) crash-2019-12-30_18.35.30-server.txt

Would be not a big issue, but you can only enable/disable async-chunks for the entire server, not for specific worlds. If you want to use SWM for some worlds and vanilla for other (bigger) worlds, this is a problem.

[Hugome]

For me even with the async-chunks disable i have the error. However it doesn't crash at Error while adding chunk to cache. Too many neighbors but at Error while removing chunk from cache. Not enough neighbors Stack without crash :

[00:33:37 ERROR]: Couldn't load chunk
java.lang.RuntimeException: Error while adding chunk to cache. Too many neighbors
	at net.minecraft.server.v1_13_R2.Chunk.H(Chunk.java:1495) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkMap.put(ChunkMap.java:38) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkMap.put(ChunkMap.java:8) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.lambda$getChunkAt$0(ChunkProviderServer.java:170) ~[paper.jar:git-Paper-624]
	at com.grinderwolf.swm.nms.v1_13_R2.CustomChunkLoader.a(CustomChunkLoader.java:211) ~[?:?]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:168) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:114) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:111) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.requestChunk(ChunkProviderServer.java:122) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.PlayerChunk.requestChunkIfNeeded(PlayerChunk.java:54) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.PlayerChunk.a(PlayerChunk.java:144) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.PlayerChunkMap.flush(PlayerChunkMap.java:151) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.WorldServer.doTick(WorldServer.java:305) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:1091) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:439) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:940) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:837) ~[paper.jar:git-Paper-624]
	at java.lang.Thread.run(Thread.java:835) [?:?]

Stack with crash :

[00:33:48 ERROR]: Encountered an unexpected exception
net.minecraft.server.v1_13_R2.ReportedException: Exception ticking world
	at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:1102) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:439) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:940) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:837) ~[paper.jar:git-Paper-624]
	at java.lang.Thread.run(Thread.java:835) [?:?]
Caused by: java.lang.RuntimeException: Error while removing chunk from cache. Not enough neighbors
	at net.minecraft.server.v1_13_R2.Chunk.I(Chunk.java:1507) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkMap.remove(ChunkMap.java:100) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkMap.remove(ChunkMap.java:8) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.unloadChunk(ChunkProviderServer.java:468) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.ChunkProviderServer.unloadChunks(ChunkProviderServer.java:403) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.WorldServer.doTick(WorldServer.java:282) ~[paper.jar:git-Paper-624]
	at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:1091) ~[paper.jar:git-Paper-624]