Tried all the fixes here to no avail. Ubuntu Software Center opens fine, but when I attempt to click the "Install" button for any of the programs, no authentication pops up (as it does on my other 12.04 install) and nothing downloads. It flashes installing... for a microsecond and then stops.
Under the edit menu I cannot alter the checkmarks on things like Ubuntu Software tab, Downloadable from the Internet. It lets me click the check mark and turns it right back off again.
APT-GET from Terminal works fine for the same programs, just wish the new Software Center functioned properly.
It seems like my permissions were locked somehow, but I don't know what directory it wants to download into and don't know how to fix it. Do I need to run Software Center as SU?
This was an upgrade from 11.10 if that matters. Thank you if anyone has a clue.