You might have an incompatible hack in your downloads folder. Have you tried removing any recent mods or objects since you last played? It could be one of those two causing the problem.
There's also the debug mode cheat (
boolprop testingcheatsenabled true) that you can enter in the neighborhood view or in the lot itself since you can still access it. If an error box pops up, take note of what it says (and the error log which might be helpful)... then you can try to press the "Reset" button. If the error still occurs, you might have to go ahead and press the "Delete" button to get rid of the object/sim/hack on that lot that's causing the error. (Don't worry too much if it's an actual sim, though... they should come back as soon as you re-enter your lot or choose the Restore Family option on the InSIMenator, so it's not permanent. )
Hope this helps you, Diesel. I hate it when my lots do something like that. :smile bi:
