I was having this problem as well. Not just with University - in fact, it started a week or so back before I installed UL. Sometimes content and saves can become corrupt. I ended up having to rename the user files to get fresh ones. I lost my saved data because apparently that was what was corrupt (when I tried to put it back into the game, the problems would resume), but at least I can play now. If you google "sims 3 troubleshooting" you can find a site that will walk you through how to do that. I would put the link here, but I'm not sure if we're allowed?
