[16:16:33] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.server.v1_9_R2.ReportedException: Exception ticking world
	at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:792) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45-internal]
Caused by: java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429) ~[?:1.8.0_45-internal]
	at java.util.HashMap$KeyIterator.next(HashMap.java:1453) ~[?:1.8.0_45-internal]
	at net.minecraft.server.v1_9_R2.PlayerChunkMap.flush(PlayerChunkMap.java:122) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.WorldServer.doTick(WorldServer.java:257) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:781) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	... 4 more
[16:16:33] [Server thread/ERROR]: 	Cause of unexpected exception was
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429) ~[?:1.8.0_45-internal]
	at java.util.HashMap$KeyIterator.next(HashMap.java:1453) ~[?:1.8.0_45-internal]
	at net.minecraft.server.v1_9_R2.PlayerChunkMap.flush(PlayerChunkMap.java:122) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.WorldServer.doTick(WorldServer.java:257) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:781) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) ~[minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [minecraft_openmod.jar:git-Spigot-8a048fe-71e5248]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45-internal]