Specific Sims cause infinite loading screen even when game music starts playing

So I’ve had this save for a long time, and now any save with two Sims, no matter how far back I go, seems to be corrupted. Every time I try to play with a household containing one of two Sims in this saves, there will be an infinite loading screen even though I can hear the game starting to play and normal game sounds are coming out. I have tried everything to fix it, like I said going back to the earliest save, taking out all Mods, but this problem persists even when I make a new save and download one of these Sims off the Gallery, they are unplayable. I would love to know what caused this so that I don’t have to be afraid of this happening to other saves.