[23:34:34 ERROR]: Could not pass event PlayerInteractEvent to HHF-Hexentials v1.0.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.craftbukkit.v1_11_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:234) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.PlayerInteractManager.a(PlayerInteractManager.java:448) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.PlayerConnection.a(PlayerConnection.java:913) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:37) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_141]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_141]
        at net.minecraft.server.v1_11_R1.SystemUtils.a(SourceFile:46) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:747) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:399) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:678) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:576) [spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_141]
Caused by: java.lang.NullPointerException
        at org.bukkit.craftbukkit.v1_11_R1.entity.CraftHumanEntity.openInventory(CraftHumanEntity.java:186) ~[spigot.jar:git-Spigot-3fb9445-6e3cec8]
        at ItemStacksAndInventories.AdminGUI.AGUI(AdminGUI.java:57) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_141]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_141]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_141]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_141]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot.jar:git-Spigot-3fb9445-6e3cec8]
        ... 17 more