---- Minecraft Crash Report ----
// Why did you do that?

Time: 04.03.20, 10:51
Description: Exception in server tick loop

java.lang.NullPointerException: Exception in server tick loop
	at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:770)
	at com.google.common.collect.SingletonImmutableSet.<init>(SingletonImmutableSet.java:47)
	at com.google.common.collect.ImmutableSet.of(ImmutableSet.java:82)
	at bny.<init>(SourceFile:16)
	at bna.a(SourceFile:28)
	at cef.k(SourceFile:76)
	at xh.a(SourceFile:175)
	at blx.<init>(SourceFile:124)
	at xh.<init>(SourceFile:175)
	at net.minecraft.server.MinecraftServer.a(SourceFile:403)
	at egy.a(SourceFile:84)
	at egy.d(SourceFile:106)
	at net.minecraft.server.MinecraftServer.run(SourceFile:634)
	at java.base/java.lang.Thread.run(Thread.java:835)


A detailed walkthrough of the error, its code path and all known details is as follows:
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-- System Details --
Details:
	Minecraft Version: 20w09a
	Minecraft Version ID: 20w09a
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 12.0.1, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode, sharing), Oracle Corporation
	Memory: 562529912 bytes (536 MB) / 973078528 bytes (928 MB) up to 2147483648 bytes (2048 MB)
	CPUs: 8
	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: 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.