CAS glitch - pictures replaced?

@emmarufus

If you have any mods move the mods folder to the desktop.
Delete localthumbcache.package file in the game folder and fix the game in Origin.
Origin/Library -right click on TS4 - option "Repair game"
You have to wait until Origin will fix all packs, not only the base game.
Turn on the game to create a new, empty mods folder. Check if a game is working now without mods.
Then copy from desktop your mods and CC and paste it in the new mods folder. First, paste script mods every time checking if the game is OK. Do the same with CC but if you have a lot of this, try the 50/50 method ( divide your CC into smaller batches for example 50 pieces in one subfolder and check these subfolders one by one) You need to find a culprit and either remove it or replace it with an updated version

If it will not work then try doing a factory reset as described in this post:
http://answers.ea.com/t5/The-Sims-4/FAQ-Troubleshooting-Steps-amp-Known-Issues/m-p/3621199

I don't work for EA

I never play with mods, so that's not the issue this time ☹️ 

@emmarufus

In this case, do the factory reset of the game folder as I mentioned above.