the_oreo_cosplay If you want to use your mods or custom content going forward, test those in the new Sims 4 folder, in batches, to see what works and what doesn't. Despite the error message, this issue is often caused by mods or cc.
Once you've sorted through those files, you can move over the contents of the saves and Tray (saved households and builds) folders, plus Screenshots and Recorded Videos if you care about those, plus Options.ini if you don't want to redo your in-game settings. The rest can be discarded.
onhkqshdnzhh It's the responsibility of mod and cc creators to keep their products compatible with the game, not the other way around. Responsible creators know this and update their content. So look for updates to whatever you want to keep using.
mary112510 Amanda_MMT Please try the clean folder I suggested earlier in the thread, and if that doesn't help, post a dxdiag. This error can also be caused by a system issue.