Description: Exception in server tick loop

java.util.concurrent.CompletionException: u: Exception generating new chunk
	at java.util.concurrent.CompletableFuture.encodeThrowable(Unknown Source)
	at java.util.concurrent.CompletableFuture.completeThrowable(Unknown Source)
	at java.util.concurrent.CompletableFuture.uniCompose(Unknown Source)
	at java.util.concurrent.CompletableFuture$UniCompose.tryFire(Unknown Source)
	at java.util.concurrent.CompletableFuture$Completion.run(Unknown Source)
	at aak.b(SourceFile:58)
	at aoz.e(SourceFile:94)
	at aoz.a(SourceFile:137)
	at aoz.run(SourceFile:105)
	at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(Unknown Source)
	at java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(Unknown Source)
	at java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
	at java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)
Caused by: u: Exception generating new chunk
	at aai.a(SourceFile:573)
	at com.mojang.datafixers.util.Either$Left.map(Either.java:38)
	at aai.a(SourceFile:556)
	... 12 more
Caused by: java.lang.ArrayIndexOutOfBoundsException: 19
	at cjq.b(SourceFile:216)
	at cly.a(SourceFile:615)
	at cjb.f(SourceFile:71)
	at cjb$d.doWork(SourceFile:263)
	at cjb.a(SourceFile:219)
	at aai.a(SourceFile:562)
	... 14 more