You haven't mentioned what you've tried to troubleshoot the problem, so here are some tips. Please forgive any repeats that you've tried.
1. Move the mods folder to desktop (for testing purposes) - This is to fully make sure it's not some outdated mods or custom content
How to Fix Problems with Mods/CC
http://www.carls-sims-4-guide.com/forum/index.php?topic=25031.msg426156#msg426156Mods and cc become outdated as we get new updates for the game. This means Mods and cc will need to be gone through regularly to find what needs to be replaced.
2. Delete game cache files and the localthumbcache.package to help with troubleshooting
Delete Game Cache Files (What and How-To)
http://www.carls-sims-4-guide.com/forum/index.php?topic=29288.msg401662#msg401662The localthumbcache.package can be found in the main Sims 4 folder
C:\Users\Username\Documents\Electronic Arts\The Sims 4
Removing the mods folder without deleting the localthumbcahche.package file from the Sims 4 folder isn't enough these two steps need to be done together.
3. Go back to a previous save that doesn't have the issue. (Before you noticed the issue)
Go Back to Previous Save or Rename a Saved Game
http://www.carls-sims-4-guide.com/forum/index.php?topic=21519.msg387147#post_GB2PS4. Check recent downloads - If the issue has just started or has been going on for a bit, check over what you've recently downloaded.
- Test with your own made lot or one from EA. This is to rule out any bugged gallery creations.
5. Repair Game:
In Origin > Games Library, right-click on Sims 4 and select Repair. - Do note this repairs the game's install files for the actual game. It does not make any changes to the saved game files. Meaning that your saved games are safe, they won't be deleted. If you'd like you can copy the Sims 4 folder to a USB key.
6. Try a Sims 4 factory reset and a new game save without mods/cc as a test.
Try a Sims 4 Factory Reset - (What & Howto)
http://www.carls-sims-4-guide.com/forum/index.php?topic=29292.msg401669#msg401669
