Royal-Ray1204 Please try this:
- Drag your whole Sims 4 folder from Document > Electronic Arts to your desktop and rename it.
- Start the game and exit.
- Download one piece of CC. I recommend furniture from peacemaker because I know for sure it has no issues. Install that directly in your Mods folder
- Restart the game and start a test save.
If that works, you can start retrying old content, but make new folders.
If it doesn't work, please let me know if you're on PC or Mac, and please show me a screenshot of your Mods folder with the full filepath.