Anyone know what has caused this...

Hello
Try turning off laptop mode and see if that helps with the issue.

I didn't think it was on laptop mode, but I'll check. Thanks @rosemow

I checked and lap top mode wasn't checked, @rosemow so any other ideas? Thanks?

Hello
Try altering the graphics settings in game options and see if that helps.
This post on the AHQ EA site thread may help
https://answers.ea.com/t5/Technical-Issues-PC/The-Sims-4-CC-Hair-Blonde-Streaks-Bug-FIX/td-p/5069642

That tells me the CC on that sim is no longer up to date with your game. I suggest checking with the maker of the CC and see if they have an update. My sister - in law saw issues just like that in her game after a C&D update in CC that was supposed to be updated for the ep and ended up having to remove the CC anyway.

C&D broke a lot of CC. Even after some cc creators fixed theirs, it’s still broken. :/

I will try that also, thanks. @Writin_Reg and @Marnetti thank you.

As some of the others have said, I had a minor version of this problem and found I needed to update many of my mods and cc's. Most of it, even the ones that hadn't been updated by creators, worked again after a redownoad.

Okay thank you all for your help, it was most appreciated, I will try everything suggested. :)

Also, isn't that alpha hair? I saw a thread with that same hair before talking about it.