My problem doesn't really have anything to with my computer system, just my game. My problem started out on a lot and my sims would try to walk in a certain area then a bubble (picture) appeared and she couldn't go there at all. I tried placing an item there and it said not to intercept with other objects. The only thing is that there isn't anything placed down in the spot. I figured my lot was just buggy, but then it started happening to a bunch of other lots. It mostly happens near walls or in corners. I disabled my custom content but it hasn't fixed anything. Any suggestions?

If it happens on all lots, then it could be something you downloaded. Test without your user files in a fresh neighbourhood to determine that:
http://www.modthesims.info/wiki.php...0Game%20Problem
Otherwise it could just be a stuck object, which you should be able to remove with the stuck object remover.
http://www.moreawesomethanyou.com/s...hp?topic=1609.0