Could not pass event InventoryCloseEvent to RPGPlayerLeveling v3.5.3
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at org.bukkit.craftbukkit.v1_9_R2.event.CraftEventFactory.handleInventoryCloseEvent(CraftEventFactory.java:871) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.PlayerConnection.a(PlayerConnection.java:1627) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.PacketPlayInCloseWindow.a(PacketPlayInCloseWindow.java:18) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.PacketPlayInCloseWindow.a(PacketPlayInCloseWindow.java:1) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.PlayerConnectionUtils$1.run(SourceFile:13) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_121]
	at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_121]
	at net.minecraft.server.v1_9_R2.SystemUtils.a(SourceFile:45) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:726) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.lang.NullPointerException
	at me.baks.rpl.manager.ItemManager.addItemPlayer(ItemManager.java:96) ~[?:?]
	at me.baks.rpl.listener.EventListener.onCloseInv(EventListener.java:512) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor336.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_121]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_121]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.9.4.jar:git-Spigot-8a048fe-5ff377a]
	... 16 more