I'm pretty new to playing Sims 4, though I've played other Sims games for years. Just started to add some custom content to the game and now, just randomly, one of my sims goes shiny suddenly while in CAS. It seems to be random - it can be when I add anything, either Maxis or CAS to her she looks shiny. It can be when I add makeup, clothing, accessories - anything. Suddenly shiny! It can also go away suddenly in CAS but when I load her into my game she is always shiny no matter what I do. I aged her down and aged her up. Still shiny.

I took custom content out and repaired my game. She wasn't shiny when I checked her without custom content, but when I added it back in, she got shiny again! Very frustrating! Does this mean I really shouldn't use any custom content in this game? Or is this sim somehow fatally glitched? I just wish the shinyness had more logic to it, but I can't really understand what's causing it!

You have to separate your cc into mods and cas items. Usually it's the game mods that creates bugs. Make sure they are all updated. Go back to the creator to look for updates.

If you still have problems take mods out and test your cas items only.

For the next part make sure it's organized so you know what you haven't tested yet, and what should work.

Then For cas items I would use the 50/50 methods. Take half your cas items out see if the problem is fixed. If it's still a problem, take out half again, if you still have the problem continue taking out half.

When you get to a point where the game works shift your mods to the previous half that didn't work.

Keep on testing what isn't working til you find the buggy item and take it out.

The creator of the offensive item would probably like to be told in a polite way