Installing glass-hd causes this problem. Even if you do not select the skin, just having it installed, and you'll run into these kinds of problems.
BTW, uninstalling won't fix it, the glass-hd skin has done permanent damage to your system files.
A clean flash is required.
I ran into a similar issue a few weeks ago where glass-hd causes a GS when go to filelist. A developer recommended to uninstall it and re-intall just the sources as packet. This overwrites the by glass-hd overwritten python files.
That works for me. Search for my posts if you like, you can find the thread where I mentioned that works for me.