Ervius' Package Creator 5.4 keeps crashing

[UndeadSquirrel]

When I select a cab, and extract it, it seems to work fine, but when I close MSCEInfEn, I get this error:

Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.

Source and destination path must have identical roots. Move will not work across volumes.

"Open package" and "Open cab file" are greyed out, and if I click "Open Initflashes Tab" or "complete package" it says, "First of all select a package!!!"

I have everything in the root of C:/, like the instructions say. Anyone know what this means?