This question already has an answer here:
I installed the newest version of cinnamon on my ubuntu 13.04 only to see how good it looks, hoping that I would still be able to use Unity if I didn't like it. It turns out it was a bad idea because cinnamon broke not only unity (to the point of complete uselessness) but also crucial system functions like the software center and bug reporting.
I tried to reinstall unity using terminal (I found a tutorial but I can't recall exactly what commands were there, 'reinstall ubuntu-desktop' or something like that) and purge cinnamon (with another tutorial) and now unity runs pretty much ok, but software center doesn't open and bug reporting causes a big crash (restart needed). Furthermore I can't access the 'appearance' option, it just doesn't start.
Is there way of restoring things as they were before cinnamon? Or I messed to much and have to reinstall ubuntu?