lilstraycat You can try one of your old saves in the clean user folder, that is if you made one. If that doesn't help, try a different (previously unplayed) household within one of your main saves—the question is whether the issue is save-wide or limited to one or a few households.
If you can't play your main households but others work, try moving one of your households to a new lot, either a blank one or a default Maxis build, i.e. one that's there when you start a new save. The problem could be the lot and not the sims.