Encountered an unexpected exceptionnet.minecraft.server.v1_11_R1.ReportedException: Exception ticking world	at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:809) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:399) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:678) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:576) [minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_112]Caused by: java.util.ConcurrentModificationException	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_112]	at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_112]	at net.minecraft.server.v1_11_R1.PlayerChunkMap$3.a(PlayerChunkMap.java:71) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.PlayerChunkMap$3.computeNext(PlayerChunkMap.java:98) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.WorldServer.j(WorldServer.java:416) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.WorldServer.doTick(WorldServer.java:255) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:798) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	... 4 more[15:38:35 ERROR]: Cause of unexpected exception wasjava.util.ConcurrentModificationException	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_112]	at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_112]	at net.minecraft.server.v1_11_R1.PlayerChunkMap$3.a(PlayerChunkMap.java:71) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.PlayerChunkMap$3.computeNext(PlayerChunkMap.java:98) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.WorldServer.j(WorldServer.java:416) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.WorldServer.doTick(WorldServer.java:255) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:798) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:399) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:678) ~[minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:576) [minecraft_server.jar:git-Spigot-b4417b8-3c48711]	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_112][15:38:35 INFO]: Tiborr69 left the game[15:38:35 ERROR]: This crash report has been saved to: /hlserver/27926/./crash-reports/crash-2018-10-15_15.38.35-server.txt