---- Minecraft Crash Report ----
// Shall we play a game?

Time: 20/03/19 19.03
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(Unknown Source)
	at java.util.HashMap$KeyIterator.next(Unknown Source)
	at net.minecraft.server.v1_12_R1.PlayerChunkMap.flush(PlayerChunkMap.java:126)
	at net.minecraft.server.v1_12_R1.WorldServer.doTick(WorldServer.java:332)
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:905)
	at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:423)
	at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:774)
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:666)
	at java.lang.Thread.run(Unknown Source)


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$HashIterator.nextNode(Unknown Source)
	at java.util.HashMap$KeyIterator.next(Unknown Source)
	at net.minecraft.server.v1_12_R1.PlayerChunkMap.flush(PlayerChunkMap.java:126)
	at net.minecraft.server.v1_12_R1.WorldServer.doTick(WorldServer.java:332)

-- Affected level --
Details:
	Level name: world
	All players: 2 total; [EntityPlayer['Vaipah'/29739, uuid='2bd93e1a-af3f-4831-bafe-25c08f1bd127', l='world', x=-10629,47, y=75,18, z=-1380,65, cx=-665, cd=-87, tl=595976, v=true, d=false](Vaipah at -10629.472264843871,75.17675927506424,-1380.65434898287), EntityPlayer['Acerhh'/31617, uuid='c3934839-8f6b-4ff4-a726-ba846276852a', l='world', x=1189,60, y=122,00, z=-6109,37, cx=74, cd=-382, tl=652340, v=true, d=false](Acerhh at 1189.5981046342863,122.0,-6109.370794601557)]
	Chunk stats: ServerChunkCache: 1200 Drop: 0
	Level seed: -1069520044122375673
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options:
	Level spawn location: World: (4,64,-24), Chunk: (at 4,4,8 in 0,-2; contains blocks 0,0,-32 to 15,255,-17), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 1602165 game time, 1709240 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 50204 (now: false), thunder time: 82991 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:905)
	at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:423)
	at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:774)
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:666)
	at java.lang.Thread.run(Unknown Source)