Crashed coming out of CAS gonna not run CAS and see what happens

downloaded sims can make the game crash while in CAS, something to do with the sim having been created with something you dont have in your game. That is a known issue.

I was editing one of the sims from my main family cuz with all the pulling out of packages they turned EA vanilla. Quick question about replacing default skins you just treat like a normal package right? Basically EAs default goes bye bye. But then there non default replacement skins how would you select those?

Correct, default skins replace EA default skins. Non Default skins tend to show up in the skintone color selector box.
Non default skintones require a separate mod, which should have been listed on the overview for the skintone.
without that extra mod, non default skintones wont work. I only have a couple, dont use them much.

Game seems stable not crashing in under 10 min but now it seems there are some other problems such as kids blowing candles on Bday cakes and not progressing. I tried supercomputer trigger age transition nada. I dunno but I think all my frustration came down to a few bugged sims I downloaded.

Ok I was still having crashing issues. But I think it was because I was loading my save and it had some of those bad sims. So I started a new game and everything is good. Thanks for the help!

Yeah, that's what I meant in one of the earlier posts, if you determined the problem to be a sim problem and that sim was in a saved game, the saved game is likely borked. Hopefully, you got it all straightened out.