---- Minecraft Crash Report ----
// Shall we play a game?

Time: 24/05/20 12:31
Description: Exception in server tick loop

java.util.concurrent.CompletionException: s: Feature placement
	at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:273)
	at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:280)
	at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:961)
	at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:926)
	at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442)
	at yk.b(SourceFile:58)
	at yk$$Lambda$3940/633430540.run(Unknown Source)
	at amc.e(SourceFile:94)
	at amc.a(SourceFile:137)
	at amc.run(SourceFile:105)
	at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1402)
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1689)
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: s: Feature placement
	at yi.a(SourceFile:580)
	at yi$$Lambda$4024/2031706555.apply(Unknown Source)
	at com.mojang.datafixers.util.Either$Left.map(Either.java:38)
	at yi.a(SourceFile:563)
	at yi$$Lambda$4021/500888430.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:952)
	... 12 more
Caused by: java.lang.UnsupportedOperationException
	at com.google.common.collect.ImmutableList.sort(ImmutableList.java:565)
	at asi.a(SourceFile:43)
	at asi.b(SourceFile:60)
	at cot.a(SourceFile:42)
	at civ.a(SourceFile:56)
	at civ.a(SourceFile:35)
	at civ.a(SourceFile:17)
	at cja.a(SourceFile:44)
	at cow.a(SourceFile:82)
	at csr.a(SourceFile:83)
	at csr.a(SourceFile:79)
	at csy.a(SourceFile:75)
	at bqd.a(SourceFile:560)
	at bqd$$Lambda$4776/893518722.accept(Unknown Source)
	at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
	at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at it.unimi.dsi.fastutil.longs.LongIterator$$Lambda$4769/910954616.accept(Unknown Source)
	at java.util.PrimitiveIterator$OfLong.forEachRemaining(PrimitiveIterator.java:189)
	at it.unimi.dsi.fastutil.longs.LongIterator.forEachRemaining(LongIterator.java:53)
	at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:512)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:502)
	at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
	at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
	at bqd.a(SourceFile:559)
	at cga.a(SourceFile:210)
	at cgc.c(SourceFile:84)
	at cgc$$Lambda$1659/1558931350.doWork(Unknown Source)
	at cgc.a(SourceFile:214)
	at yi.a(SourceFile:569)
	... 17 more


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
	Minecraft Version: 20w21a
	Minecraft Version ID: 20w21a
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 1349351608 bytes (1286 MB) / 2147483648 bytes (2048 MB) up to 2147483648 bytes (2048 MB)
	CPUs: 4
	JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
	Player Count: 1 / 8; [yx['lallikus'/72, l='ServerLevel[MC VAN]', x=470.07, y=72.00, z=-490.02]]
	Data Packs: vanilla
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.