how to fix yellow skin?? (the sims 4)

@Hznf25  That's clearly a custom content issue.  Please move your entire Mods folder to the desktop, delete localthumbcache.package, and test.  As long as you don't save your progress with the mods and cc absent, your existing saves should be fine once you add most of the content back in.

The point here is to make the yellow skin disappear, then add back content until it reappears—you'll then know which item(s) to remove.  You may or may need to take your sims into CAS to change their skin after the bad cc is gone, but you'll find that out as soon as you test with no cc present at all.

If you have a lot of content to sort through, the 50/50 method can make the process more efficient.

https://modthesims.info/wiki.php?title=Game_Help:Finding_Problem_Custom_Content#The_50.25_Method