Game Crashes at Buffet World creation (Preparing spawn area 79%)

I just tried out the new snapshot. After i already created a buffet world with void in Overworld i tried Mooshroom Shore Island with Overworld an after a while the Screen just showed this:

I opened the log file to see if there is some sort of crash, and i found that a crash report has been made, but minecraft is still open.
Crash report:

Full log:

PS: Minecraft didn't respond to clicking the red X or doing ALT-F4 so i had to close it with the task manager.

Description: Exception in server tick loop

java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.ArrayIndexOutOfBoundsException: 61
	at net.minecraft.server.MinecraftServer.i_(SourceFile:396)
	at dbc.a(SourceFile:116)
	at dbc.d(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:504)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.concurrent.ExecutionException: java.lang.ArrayIndexOutOfBoundsException: 61
	at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2272)
	at net.minecraft.server.MinecraftServer.i_(SourceFile:394)
	... 4 more
Caused by: java.lang.ArrayIndexOutOfBoundsException: 61
	at wj.a(SourceFile:106)
	at wj.c(SourceFile:64)
	at bjg.a(SourceFile:33)
	at bjn.a(SourceFile:85)
	at bjn.a(SourceFile:81)
	at bji.a(SourceFile:52)
	at bjo.a(SourceFile:144)
	at sm.a(SourceFile:230)
	at bmk.a(SourceFile:138)
	at bmw.a(SourceFile:76)
	at bmw.a(SourceFile:17)
	at bog.a(SourceFile:22)
	at bog.a(SourceFile:15)
	at bog.a(SourceFile:10)
	at bql.a(SourceFile:18)
	at bql.a(SourceFile:12)
	at blk.a(SourceFile:27)
	at avq.a(SourceFile:513)
	at biy.a(SourceFile:110)
	at sv.a(SourceFile:12)
	at su.a(SourceFile:33)
	at bjc.a(SourceFile:85)
	at ta.a(SourceFile:54)
	at ta.a(SourceFile:23)
	at zy$a.a(SourceFile:143)
	at zy$a$$Lambda$934/1982185364.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture$AsyncApply.exec(CompletableFuture.java:501)
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:902)
	at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1689)
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1644)
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)