Whenever my game crashes I use the Crash Log Analyzer to see what (most likely) the issue was, and 9/10 times it was a 'ran out of memory' issue. That answer can be caused by many things though, in my case (I play in borderless window) when I would switch the window to another program a few times and then tried to save the game, it would almost always crash. So now when I play, I just don't switch windows or tab to another program and haven't had any crashes. But for others the answer isn't so easy to find.
I asked this question on Twitter and Reddit - you can read the responses if you'd like, and I wanted to ask the same thing here just to see if game crashing is an issue for you and when it happens and if you know a specific reason why it's happening.https://www.reddit.com/r/Sims3/comments/vnr9wd/how_often_does_your_game_crash/