[23:42:51 ERROR]: Could not pass event PlayerDeathEvent to CraftTrack v1.0
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[mc.jar:git-Spigot-1387]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[mc.jar:git-Spigot-1387]
at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30) ~[mc.jar:git-Spigot-1387]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [mc.jar:git-Spigot-1387]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [mc.jar:git-Spigot-1387]
at org.bukkit.craftbukkit.v1_7_R2.event.CraftEventFactory.callPlayerDeathEvent(CraftEventFactory.java:366) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.EntityPlayer.die(EntityPlayer.java:389) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.EntityLiving.damageEntity(EntityLiving.java:739) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.EntityHuman.damageEntity(EntityHuman.java:751) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.EntityPlayer.damageEntity(EntityPlayer.java:468) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.EntityHuman.attack(EntityHuman.java:923) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.PlayerConnection.a(PlayerConnection.java:1144) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.PacketPlayInUseEntity.a(SourceFile:55) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.PacketPlayInUseEntity.handle(SourceFile:10) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.NetworkManager.a(NetworkManager.java:148) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.ServerConnection.c(ServerConnection.java:77) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.MinecraftServer.v(MinecraftServer.java:705) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.DedicatedServer.v(DedicatedServer.java:273) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.MinecraftServer.u(MinecraftServer.java:568) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.MinecraftServer.run(MinecraftServer.java:474) [mc.jar:git-Spigot-1387]
at net.minecraft.server.v1_7_R2.ThreadServerApplication.run(SourceFile:618) [mc.jar:git-Spigot-1387]
Caused by: java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:859) ~[?:1.7.0_80]
at java.util.ArrayList$Itr.next(ArrayList.java:831) ~[?:1.7.0_80]
at pl.eldzi.crafttrack.events.CraftTrackListener.onKill(CraftTrackListener.java:23) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_80]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_80]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_80]
at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_80]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[mc.jar:git-Spigot-1387]
... 20 more