Raid bug

A raid had taken place in the villagers. However, when the last attacker was killed, a crash occurred and the game went out.

18w49a\: [^crash-2018-12-11_19.16.58-server.txt]

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

Time: 18. 12. 11 오후 7:16
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
	at java.util.HashMap$KeyIterator.next(HashMap.java:1453)
	at ui.b(SourceFile:105)
	at arm.j(SourceFile:230)
	at arm.l(SourceFile:327)
	at aro.a(SourceFile:80)
	at uk.a(SourceFile:205)
	at net.minecraft.server.MinecraftServer.b(SourceFile:779)
	at net.minecraft.server.MinecraftServer.a(SourceFile:716)
	at doq.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:582)
	at java.lang.Thread.run(Thread.java:745)


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$HashIterator.nextNode(HashMap.java:1429)
	at java.util.HashMap$KeyIterator.next(HashMap.java:1453)
	at ui.b(SourceFile:105)
	at arm.j(SourceFile:230)
	at arm.l(SourceFile:327)
	at aro.a(SourceFile:80)
	at uk.a(SourceFile:205)

-- Affected level --
Details:
	Level name: 새로운 세계
	All players: 2 total; [um['mine2960'/115790, l='새로운 세계', x=-275.57, y=66.18, z=-287.64], um['ZKASA3021'/119446, l='새로운 세계', x=-303.15, y=70.75, z=-286.71]]
	Chunk stats: ServerChunkCache: 2389
	Level seed: 8252064537936176757
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: {}
	Level spawn location: World: (-256,68,-240), Chunk: (at 0,4,0 in -16,-15; contains blocks -256,0,-240 to -241,255,-225), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
	Level time: 272730 game time, 327676 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 124125 (now: false), thunder time: 29730 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.b(SourceFile:779)
	at net.minecraft.server.MinecraftServer.a(SourceFile:716)
	at doq.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:582)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 18w49a
	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: 1441472136 bytes (1374 MB) / 2818572288 bytes (2688 MB) up to 4294967296 bytes (4096 MB)
	JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx4G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
	Player Count: 2 / 8; [um['mine2960'/115790, l='새로운 세계', x=-275.57, y=66.18, z=-287.64], um['ZKASA3021'/119446, l='새로운 세계', x=-303.15, y=70.75, z=-286.71]]
	Data Packs: vanilla
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.