---- Minecraft Crash Report ----
// Oops.

Time: 27/12/18 15:40
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1442)
	at java.util.HashMap$KeyIterator.next(HashMap.java:1466)
	at uo.b(SourceFile:105)
	at asf.j(SourceFile:229)
	at asf.l(SourceFile:326)
	at ash.a(SourceFile:80)
	at uq.a(SourceFile:206)
	at net.minecraft.server.MinecraftServer.b(SourceFile:836)
	at tr.b(SourceFile:337)
	at net.minecraft.server.MinecraftServer.a(SourceFile:773)
	at net.minecraft.server.MinecraftServer.run(SourceFile:639)
	at java.lang.Thread.run(Thread.java:748)


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

-- Head --
Thread: Server thread
Stacktrace:
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1442)
	at java.util.HashMap$KeyIterator.next(HashMap.java:1466)
	at uo.b(SourceFile:105)
	at asf.j(SourceFile:229)
	at asf.l(SourceFile:326)
	at ash.a(SourceFile:80)
	at uq.a(SourceFile:206)

-- Affected level --
Details:
	Level name: moowcows2bf
	All players: 2 total; [us['THE_WYNER'/111459, l='moowcows2bf', x=179.56, y=57.99, z=20.34], us['david_powell'/111863, l='moowcows2bf', x=175.38, y=67.00, z=4.51]]
	Chunk stats: ServerChunkCache: 2067
	Level seed: -7716553145357750077
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: {}
	Level spawn location: World: (128,67,0), Chunk: (at 0,4,0 in 8,0; contains blocks 128,0,0 to 143,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 19952345 game time, 65903 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 2449 (now: false), thunder time: 85142 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.b(SourceFile:836)
	at tr.b(SourceFile:337)
	at net.minecraft.server.MinecraftServer.a(SourceFile:773)
	at net.minecraft.server.MinecraftServer.run(SourceFile:639)
	at java.lang.Thread.run(Thread.java:748)

-- System Details --
Details:
	Minecraft Version: 18w50a
	Operating System: Linux (amd64) version 4.19.8-1-default
	Java Version: 1.8.0_181, Oracle Corporation
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 1195759144 bytes (1140 MB) / 3499098112 bytes (3337 MB) up to 5616697344 bytes (5356 MB)
	JVM Flags: 0 total; 
	Player Count: 2 / 4; [us['THE_WYNER'/111459, l='moowcows2bf', x=179.56, y=57.99, z=20.34], us['david_powell'/111863, l='moowcows2bf', x=175.38, y=67.00, z=4.51]]
	Data Packs: vanilla
	Is Modded: Unknown (can't tell)
	Type: Dedicated Server (map_server.txt)