[24 May 2015 09:07:01] [Server thread/ERROR]: Could not pass event InventoryClickEvent to HeadHunting v1.3.2
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1607) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_45]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_45]
	at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:60) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:778) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:356) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:716) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:618) [spigot.jar:git-JustSpigot-509c95b-a486600]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45]
Caused by: java.util.ConcurrentModificationException
	at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:966) ~[?:1.8.0_45]
	at java.util.LinkedList$ListItr.next(LinkedList.java:888) ~[?:1.8.0_45]
	at com.google.common.collect.Iterators$9.next(Iterators.java:939) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at com.google.common.collect.Iterators.addAll(Iterators.java:357) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at com.google.common.collect.Lists.newArrayList(Lists.java:147) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.UserCache.a(UserCache.java:235) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.UserCache.c(UserCache.java:216) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.UserCache.a(UserCache.java:124) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.UserCache.a(UserCache.java:97) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at net.minecraft.server.v1_8_R3.UserCache.getProfile(UserCache.java:147) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.getOfflinePlayer(CraftServer.java:1304) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at org.bukkit.Bukkit.getOfflinePlayer(Bukkit.java:741) ~[spigot.jar:git-JustSpigot-509c95b-a486600]
	at com.pwncraftpvp.hh.core.HPlayer.<init>(HPlayer.java:32) ~[?:?]
	at com.pwncraftpvp.hh.core.Head.getPlayerSellPrice(Head.java:125) ~[?:?]
	at com.pwncraftpvp.hh.utils.Utils.getPlayerHeadItem(Utils.java:268) ~[?:?]
	at com.pwncraftpvp.hh.core.Events.inventoryClick(Events.java:301) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor200.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_45]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_45]
	at org.bukki