Pitch Black Sims.

Hiya, I've got a kind of silly problem happening in the sims 4. I truly cannot fix it for the life of me and I'm hoping you could help me solve it.

Basically, I'm having this issue where one family of my sims will turn literally pitch black. (I've played with the household for over a week in real life and this has just suddenly happened) - I've tried disabling mods, updating my mods, removing old mods, recovering old saves and even repairing the game three times. (None of which worked) - The most successful attempt has come from me evicting then replacing the 'glitched' family with an older version from my library. This only works until I exit the game as it then turns them back to being pitch black. The issues still persists in Create a Sim and in Live Mode but I'm playing with 2 spellcaster sims? I'm unsure if that causes issues. Nothing that I've tried has fixed this issue and I was unable to find resources online to help me with such a specific problem so I've resorted to this haha. Any ways to fix it?