I'll assume that was directed at me and not Chuckles, yes I do use that on non challenge games and I reset them with it which fixed them but why so many in the first place.
I'm wondering if the swimming has something to do with it, odd as that may sound, all the sunken sims were on the middle island having had to cross over the river and the bridges were behaving oddly too. I'll probably never know, I'm currently reinstalling and reverting to 1.39, the features added with this I can live without for the time being, but the problems are making my game unplayable and it's also stopped me from carrying on with my townie dynasty game because of the marriage bug.
I'm usually cautious about updating and wait a few weeks but curiosity got the better of me this time, lesson learned, I'll wait for the bug reports in future as I always have before.