It doesn't look like your getting any help on this
but I was just wondering if you have this issue with any other lot besides the one you downloaded from GOS? because if not maybe it's a problem with the lot or a bad hack/mod I would say to delete the lot and make some more sims and see how the game works then, BUT if this is a problem with more than just this lot I would say it is likely a graphics card issue or something else
hope you get it working again
