I haven't had time to read all 22 pages, but here's my experience.
Family in Riverview, Base game, no EP or CC:
This was a brand new family. One of the children had a birthday, and shortly after that the "freezing" started. All Sims stop moving, time stops, but simple animations (music, sleep...) continue. I had already saved the game before I realized what was happening. I went back to play this save later (knowing that it had issues) and at some point I realized that the freezing had stopped. The only thing I can remember is that I spent a lot of time in Build Mode. So this save is fine now, I didn't do anything to fix it.
Family in Riverview, Base game and WA, no CC:
This family is a few generations in. Mom had a birthday to Adult, and shortly after that the freezing started. I hadn't saved yet, so I immediately quit the game. When I loaded that save, she did the birthday thing again and I played for awhile, but I didn't see the freezing start. So I thought maybe I outsmarted it and saved. When I loaded that save again, it had the freezing. Even though I have WA now, I've never done anything WA related yet. When this family freezes, it lasts longer than the other family (around 30 seconds before the move again).
I tried clearing the cache the time but it didn't help. I haven't tried any other mod yet. Knowing that I somehow beat it last time, I'm hoping for that to happen again.
I have a 1 year old computer that had great specs when I bought it (still does) and I run all the settings on high. Have a low spec computer will give you grief with this game, but it's not the cause of the freezing problem.
