walls are dissapearing when placing paint or wallpapers down

@Cirisimstarsi

I can see Bryone is busy.
For now you can try resetting the whole game folder. There is a chance that this will fix your game.
Go to menu Start/ Documents/ElectronicArts - inside will be The Sims4 folder
Step 1. Rename this The Sims4 folder to "The Sims4 old" /Right click on the game folder - option "rename"
Step 2. Fix the game in Origin /Library - right click on TS4 - option "Repair game"
Step 3. Turn on the game - new game folder will be create and you will have two - one old , one new
Step 4. Take random sim and start new game. Check if you still have this problem in the new created game folder
If problem desaperaed
Step 5. Delete in the new game folder following folders:
"saves" and Tray.
Step 6. Go to "The Sims 4 old" folder and copy - your "saves " folder. Right click on the folder - option - copy
Step 7 Paste this folder in new created game folder. / Right click on the new game folder - option - paste
Step 8. Do the same with Tray folder
Step 9. Turn on the game , go to your save and check if all is OK now
Step 10. If game is working properly - delete "The Sims4 old" folder