This happens when I go onto a world or a multiplayer server.

[16:05:37] [Client thread/FATAL]: Unreported exception thrown!
java.lang.NullPointerException
at invtweaks.InvTweaks.handleAutoRefill(InvTweaks.java:575) ~[InvTweaks.class:?]
at invtweaks.InvTweaks.onTickInGame(InvTweaks.java:121) ~[InvTweaks.class:?]
at invtweaks.forge.ForgeClientTick.onTick(ForgeClientTick.java:24) ~[ForgeClientTick.class:?]
at cpw.mods.fml.common.eventhandler.ASMEventHandler_7_ForgeClientTick_onTick_ClientTickEvent.invoke(.dynamic) ~[?:?]
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:39) ~[ASMEventHandler.class:?]
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:108) ~[EventBus.class:?]
at cpw.mods.fml.common.FMLCommonHandler.onPostClientTick(FMLCommonHandler.java:315) ~[FMLCommonHandler.class:?]
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:2058) ~[azd.class:?]
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:951) ~[azd.class:?]
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:869) [azd.class:?]
at net.minecraft.client.main.Main.main(SourceFile:103) [Main.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_45]
at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_45]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134) [launchwrapper-1.9.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]
---- Minecraft Crash Report ----
// My bad.

Time: 12/01/14 16:05
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
at invtweaks.InvTweaks.handleAutoRefill(InvTweaks.java:575)
at invtweaks.InvTweaks.onTickInGame(InvTweaks.java:121)
at invtweaks.forge.ForgeClientTick.onTick(ForgeClientTick.java:24)
at cpw.mods.fml.common.eventhandler.ASMEventHandler_7_ForgeClientTick_onTick_ClientTickEvent.invoke(.dynamic)
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:39)
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:108)
at cpw.mods.fml.common.FMLCommonHandler.onPostClientTick(FMLCommonHandler.java:315)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:2058)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:951)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:869)
at net.minecraft.client.main.Main.main(SourceFile:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)