Try this:
::smilieiforgetwhi:: Load the game, and when you get to the neighborhood view of whichever neighborhood you choose, call up the cheat console (
CTRL + Shift + C) and type in
boolprop testingcheatsenabled true and press
Enter.
::smilieiforgetwhi:: After you do that, load up your "problem" lot and wait until it loads up completely. If all goes as suspected, an error box will pop up right before (or sometimes after) the lot loads up.
Take note of what type of error it is and the name of the error log that is dumped into the Logs folder.
That's the log that's most likely to help out in this situation. And for a "quick" skip-over for passing the error by, click the "Delete" option when the error pops up. It removes whatever object/sim that's causing the error. If it's a sim, don't worry too much about it, as it's not a permanent deletion... you can easily get them back by either exiting and re-entering the lot, or by using the "Restore Family" option on the InSIMenator's summoner object.

That should help. If you can, attach the error logs in your next post... someone that's "literate" in that area should be able to figure what might be throwing you an error.
And just to be sure, remove any custom careers, foods, and the latest hacks you've put in your downloads folder, then try the above if the game still gets stuck at those points. :angel: