Dvnt

I love you.

That must be it, thanks. Can you give an example on what would be in the packet handler to open the GUI?

GUI handler: Opening GUI:

It's being sent from a GUI extending GuiContainer via: register code in main:

Produces same exception. It's weird because it does actually set it to null.

In my packet handler, I'm getting an exception every time I attempt to manipulate any item in a slot that isn't the hot-bar (0-8 is fine, 9-40 causes exception) Example, this code (line 16): produces this exception (yes there's an item in slot 9): Any ideas? Need more information?