@yourawizardkay Please uninstall the EA App with Revo Uninstaller (the free version is fine). Then restart your computer, reinstall the App, and run both Steam and the EA App as an admin: right-click on each desktop shortcut and select "Run as administrator." Only try to launch Sims 4 with both apps up and fully loaded.
@yourawizardkay Please create a new admin Windows account and try playing there. Make it local, as in, don't link it to your Microsoft account. You'll be able to (try to) launch Sims 4 without reinstalling anything, but your saves and other user content won't be available. That's fine for now; just let me know whether the game opens.
If it doesn't, please post a screenshot of the error. Please also run a dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/
