I have this issue in my new survival world in 18w22b from 18w21a. After entering nether and traveling for 2 chunks the game crashes and it says:

---- Minecraft Crash Report ----
// Uh... Did I do that?

Time: 30.05.2018 17:32
Description: Exception generating new chunk

java.util.concurrent.ExecutionException: java.lang.UnsupportedOperationException
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2237)
at sl.c(SourceFile:126)
at st.a(SourceFile:84)
at su.c(SourceFile:143)
at sm.i_(SourceFile:223)
at net.minecraft.server.MinecraftServer.w(SourceFile:693)
at net.minecraft.server.MinecraftServer.v(SourceFile:626)
at dik.v(SourceFile:156)
at net.minecraft.server.MinecraftServer.run(SourceFile:531)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.UnsupportedOperationException
at bpy.e(SourceFile:100)
at sr.i(SourceFile:245)
at sr.a(SourceFile:238)
at bvd.a(SourceFile:133)
at bvd.a(SourceFile:42)
at bvd.a(SourceFile:14)
at bza.a(SourceFile:23)
at bza.a(SourceFile:14)
at bsn.a(SourceFile:27)
at bca.a(SourceFile:515)
at bqa.a(SourceFile:109)
at ta.a(SourceFile:12)
at sz.a(SourceFile:34)
at bqe.a(SourceFile:95)
at tg.a(SourceFile:62)
at tg.a(SourceFile:25)
at agi$a.a(SourceFile:131)
at agi$a$$Lambda$1619/297142314.apply(Unknown Source)
at java.util.concurrent.CompletableFuture$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)

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

– Head –
Thread: Server thread
Stacktrace:
at sl.a(SourceFile:170)

– Chunk to be generated –
Details:
Location: -20,-18
Position hash: -73014444052
Generator: brt@10964738
Stacktrace:
at sl.a(SourceFile:170)
at sl.c(SourceFile:129)
at st.a(SourceFile:84)
at su.c(SourceFile:143)
at sm.i_(SourceFile:223)
at net.minecraft.server.MinecraftServer.w(SourceFile:693)
at net.minecraft.server.MinecraftServer.v(SourceFile:626)
at dik.v(SourceFile:156)
at net.minecraft.server.MinecraftServer.run(SourceFile:531)
at java.lang.Thread.run(Thread.java:745)

– Affected level –
Details:
Level name: Hi There!
All players: 1 total; [so['JosephAlbert'/97, l='Hi There!', x=-113.22, y=92.00, z=-84.94]]
Chunk stats: ServerChunkCache: 600 Drop: 0
Level seed: 7518713402979014116
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options: {}
Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 0 game time, 0 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: ~_ERROR~ NullPointerException: null

– System Details –
Details:
Minecraft Version: 18w22b
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 260389280 bytes (248 MB) / 620756992 bytes (592 MB) up to 1073741824 bytes (1024 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [so['JosephAlbert'/97, l='Hi There!', x=-113.22, y=92.00, z=-84.94]]
Data Packs: vanilla
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

I tried it on my 1.12.2 survival world and it was fine, I also tried it on a different world, and it was fine in that world too. So this means my world is corrupted? pls help. EDIT: I checked my java version it is up to date.