What does this error mean?

[Hotelmariofan]

Title: What does this error mean?

Version: 3.1.2

OS: Windows 7 Home Premium 64bit

Java Version: 1.7.0_11-b21

Description of Problem:

I just get this in my server logs/cmd

Error Messages:

Error Log:

2013-02-14 23:53:04 [sEVERE] Could not pass event PlayerInteractEvent to Modifyw

orld

org.bukkit.event.EventException



        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja

va:304)



        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav

a:62)



        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j

ava:482)



        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j

ava:467)



        at org.bukkit.craftbukkit.event.CraftEventFactory.callPlayerInteractEven

t(CraftEventFactory.java:177)



        at net.minecraft.server.ItemInWorldManager.interact(ItemInWorldManager.j

ava:302)



        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:647)



        at net.minecraft.server.Packet15Place.handle(SourceFile:39)



        at net.minecraft.server.NetworkManager.b(NetworkManager.java:234)



        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:119)



        at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:8

3)



        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:579)



        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:467)



        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)



Caused by: java.lang.NullPointerException



        at ru.tehkode.modifyworld.ModifyworldListener.getMaterialPermission(Modi

fyworldListener.java:88)



        at ru.tehkode.modifyworld.ModifyworldListener.getMaterialPermission(Modi

fyworldListener.java:92)



        at ru.tehkode.modifyworld.ModifyworldListener.getBlockPermission(Modifyw

orldListener.java:96)



        at ru.tehkode.modifyworld.ModifyworldListener.getObjectPermission(Modify

worldListener.java:161)



        at ru.tehkode.modifyworld.ModifyworldListener.assemblePermission(Modifyw

orldListener.java:146)



        at ru.tehkode.modifyworld.ModifyworldListener.permissionDenied(Modifywor

ldListener.java:122)



        at ru.tehkode.modifyworld.handlers.PlayerListener.onPlayerInteract(Playe

rListener.java:216)



        at sun.reflect.GeneratedMethodAccessor23.invoke(Unknown Source)



        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)



        at java.lang.reflect.Method.invoke(Unknown Source)



        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja

va:302)



        ... 13 more

[Scoapimp]

Bump. I'm having the Same Issue.