I put the Kethane pack into the plugins folder and opened KSP, but when I tried to attach the parts to my rockets, the game glitched and I couldn't do anything. I couldn't hit the exit button to get out of the VAB. Also, I tried to unstick the piece I had selected from my mouse, and it didn't work, like, I would hit the delete button and it wouldn't delete, and when I clicked in the parts side of the screen, it wouldn't delete itself. I have a clean copy of KSP (from Steam), no mods (other than Kethane, but now that's deleted too), and my version is 0.21.1. Also, I have windows 8, if that's of any meaning. Please help.