Sims won't bathe, shower, or swim.

@BearLandBucFan I've seen some Simmers suggest that there's an out-of-date mod related to outfit changing causing this. I'd suggest starting with those. You might need to do a 50-50: his means organizing the files there into bite-size batches and testing one batch at a time. For each test, delete the file called localthumbcache, then put only that batch in Mods. If your game opens, set that batch aside as "cleared" and delete localthumbcache again. If it doesn't open, take out half the batch and see if you're closer to finding the culprit. Remember to delete localthumbcache each time. You'll find some 50-50 method tutorials online too.