Whenever I age up my sim her skin shows up as broken

I have no clue what could be causing it, as so far I've tried all I can think of. (My game is entirely up to date)

I've been told the error showing up on her skin means there is a mesh or texture missing but I'm not sure what could be missing. She had a loose tooth as a kid but I removed all buffs and traits relating to that and the issue still persisted. I also took off everything her sim was wearing to make sure it wasn't broken CC I had downloaded, but that didn't solve anything. Then I repaired my game and the same issue continued. Even when I turn of all of my mods it still shows up. But this issue doesn't happen with the girl's twin sister, only her. Could I have deleted some file necessary for her to not be broken? Or is this an entirely new glitch? It's never happened before and every other sim at this point has had no trouble aging up.

I'll also show a picture of her twin to show that there's no problem with her.