---- Minecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 5/23/18 4:02 PM
Description: Exception in server tick loop

java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.ArrayIndexOutOfBoundsException
	at net.minecraft.server.MinecraftServer.g_(SourceFile:393)
	at dii.a(SourceFile:116)
	at dii.d(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:502)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.concurrent.ExecutionException: java.lang.ArrayIndexOutOfBoundsException
	at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2272)
	at net.minecraft.server.MinecraftServer.g_(SourceFile:391)
	... 4 more
Caused by: java.lang.ArrayIndexOutOfBoundsException
	at it.unimi.dsi.fastutil.shorts.ShortArrays.grow(ShortArrays.java:265)
	at it.unimi.dsi.fastutil.shorts.ShortArrayList.grow(ShortArrayList.java:308)
	at it.unimi.dsi.fastutil.shorts.ShortArrayList.add(ShortArrayList.java:322)
	at bqq.a(SourceFile:61)
	at sq.a(SourceFile:23)
	at bbt.a(SourceFile:9)
	at cae.a(SourceFile:145)
	at bzg.a(SourceFile:117)
	at bzg.a(SourceFile:62)
	at bzg.a(SourceFile:19)
	at bzh.a(SourceFile:27)
	at bpy.a(SourceFile:64)
	at tc.a(SourceFile:14)
	at sx.a(SourceFile:34)
	at bqc.a(SourceFile:87)
	at td.a(SourceFile:59)
	at td.a(SourceFile:23)
	at agg$a.a(SourceFile:143)
	at agg$a$$Lambda$1324/52186391.apply(Unknown Source)
	at java.util.concurrent.CompletableFuture$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:
---------------------------------------------------------------------------------------

-- System Details --
Details:
	Minecraft Version: 18w21a
	Operating System: Windows 8.1 (amd64) version 6.3
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 171879736 bytes (163 MB) / 503316480 bytes (480 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: 0 / 8; []
	Data Packs: vanilla
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.