My game has been functioning fine after the most recent patch I had an issue with a new lot from the new pack that I hadn't been to before. I thought it was just cause it's new well I got around that error and the game was working again. When it gave the error I could immediately go back to the world and the game said the lot was incomplete. I was unable to get a screenshot but it was similar to the bug we had with uni graduates after they were placed once the ceremony was complete.
So today, assuming it was fine because I couldn't find the "broken" lot again I readded my mods for testing and got the error again this time with thriftea I was able to load it up in build mode but nothing was missing and I didn't have to fix it going to another lot first got around that and it worked fine and is no longer marked incomplete.
The game didn't register my screenie of the error ugh.
I have two copies of the same damaged save, mind you it has several hours in it so it started suddenly reopened the first copy got the error this time and it's the same lot from the first time. I checked and again it's not actually incomplete.
TLDR
Wo mods, after several hours of play
W mods first family switch and travel
Both could get around not sure should I remove mods again and start a fresh save to check?