Originally Posted by kiwidude
When you do the Generate Cover install, then if you have not uninstalled the old version manually first you will see an error message like BaconButty, theducks and sugarcandy243 all posted. This is a bug in calibre, not the plugin. Just click ok, close and restart calibre and all will be fine.
I installed it, clicked OK on the error message, restarted and it came up fine. Tried out a basic cover creation with no problem.