20w45a Snapshot: Game crash

I have only experienced this once in my creative world. Don't know if it will be persistent but just in case.

Crash report: 

20w45a\: [^crash-2020-11-06_10.10.50-client.txt]

---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 11/6/20 10:10 AM
Description: Batching chunks

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
	at java.util.HashMap$KeyIterator.next(HashMap.java:1453)
	at java.util.AbstractSet.removeAll(AbstractSet.java:174)
	at efu$c.a(SourceFile:388)
	at efu$c.a(SourceFile:224)
	at efu$c$b.a(SourceFile:434)
	at efu.a(SourceFile:135)
	at efu$$Lambda$5330/650814456.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:952)
	at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:926)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
	at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1624)
	at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1610)
	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)


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

-- Head --
Thread: Render thread
Stacktrace:
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
	at java.util.HashMap$KeyIterator.next(HashMap.java:1453)
	at java.util.AbstractSet.removeAll(AbstractSet.java:174)
	at efu$c.a(SourceFile:388)

-- Affected level --
Details:
	All players: 1 total; [eck['Miquorice'/328, l='ClientLevel', x=-99.27, y=82.78, z=176.18]]
	Chunk stats: 1369, 1041
	Level dimension: minecraft:overworld
	Level spawn location: World: (16,4,32), Section: (at 0,4,0 in 1,0,2; chunk contains blocks 16,0,32 to 31,255,47), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 7672954 game time, 1 day time
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at dzr.a(SourceFile:363)
	at dmh.c(SourceFile:2198)
	at efu.a(SourceFile:139)
	at efu$$Lambda$5331/300807318.accept(Unknown Source)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
	at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1624)
	at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1610)
	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)

-- System Details --
Details:
	Minecraft Version: 20w45a
	Minecraft Version ID: 20w45a
	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: 942609416 bytes (898 MB) / 1811939328 bytes (1728 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
	Launched Version: 20w45a
	Backend library: LWJGL version 3.2.2 build 10
	Backend API: ~~ERROR~~ IllegalStateException: Rendersystem called from wrong thread
	GL Caps: Using framebuffer using OpenGL 3.0
	Using VBOs: Yes
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Graphics mode: fancy
	Resource Packs: vanilla
	Current Language: English (United Kingdom)
	CPU: 4x Intel(R) Core(TM) i5-6300HQ CPU @ 2.30GHz