[17:26:52] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.server.v1_12_R1.ReportedException: Exception ticking world
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:812) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_232]
Caused by: java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1445) ~[?:1.8.0_232]
	at java.util.HashMap$KeyIterator.next(HashMap.java:1469) ~[?:1.8.0_232]
	at net.minecraft.server.v1_12_R1.PlayerChunkMap.flush(PlayerChunkMap.java:122) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.WorldServer.doTick(WorldServer.java:320) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:801) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	... 4 more
[17:26:52] [Server thread/ERROR]: 	Cause of unexpected exception was
java.util.ConcurrentModificationException: null
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1445) ~[?:1.8.0_232]
	at java.util.HashMap$KeyIterator.next(HashMap.java:1469) ~[?:1.8.0_232]
	at net.minecraft.server.v1_12_R1.PlayerChunkMap.flush(PlayerChunkMap.java:122) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.WorldServer.doTick(WorldServer.java:320) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:801) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_232]
[17:26:52] [Server thread/ERROR]: This crash report has been saved to: /home/minecraft/multicraft/servers/server17/./crash-reports/crash-2020-01-18_17.26.52-server.txt
[17:26:52] [Server thread/INFO]: Stopping server