ThemeChanger wont do .guiKit's?

Hello, I had previously downloaded ShapeShifter and loved it (until the demo went bye-bye) So I went to a freeware program, ThemeChanger, disabled ShapeShifter and am trying to apply a theme.

Only problem is is hat is wont open my .guiKit and say I need to enable my useless ShapeShifter!

I dont know what to do D:

Much help appreciated, thank you