@LinealSoul: Your first guess was correct.
One of your images is badly formatted. It just happens to break the whole cycle completely until it's fixed and the framework restarted (because reasons ;p).
And yeah, correct again, you don't need Python if you don't intend to use cover mode.
Unless you flag one of my hacks for complete uninstall (through their respective KUAL menus), the uninstall package will *never* delete the folder, because these can (and should ;p) contain user-provided content, which I have no right to annihilate without warning
.
TL;DR: Everything went according to plan, you just have one (or more) finicky images in your set.