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[22:42:04] [Server thread/ERROR]: Could not pass event InventoryClickEvent to System v2.2.4
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1630) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_292]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_292]
	at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_292]
Caused by: java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:911) ~[?:1.8.0_292]
	at java.util.ArrayList$Itr.next(ArrayList.java:861) ~[?:1.8.0_292]
	at de.iraphi.rax.menubuilder.inventory.InventoryListener.onInventoryClick(InventoryListener.java:112) ~[?:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_292]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_292]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_292]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_292]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	... 15 more