@MsKayCeeSim52 Did you try playing in a new admin Windows account? If not, please do so now. The account should be local, as in, don't link it to your Microsoft account.
If that doesn't help either, please run a (fresh) dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/
How can I make a new admin account? I don't have extra email addresses, and I'm not sure how to make an account that is NOT linked to msn. That seems unlikely to help when the problem is the game files are corrupt or missing.
@MsKayCeeSim52 There's nothing obvious in your dxdiag, just some Windows update errors and a few crashes of other apps. That likely means that Sims 4 is being blocked from starting rather than crashing, which is not a surprise given the error.
The point of the new account is that it's entirely possible that the game data is NOT missing or corrupt, that the problem is the games ability to access the user folder. Sims 4 errors are notoriously unhelpful, either too vague to be of any use or blatantly inaccurate. The new user account would have a new Documents folder, one that hasn't been affected by anything else on your computer. That means nothing should be blocking access. If it works, great; if not, we look elsewhere.
Here's how to make a local account, and the whole point is that you don't need an email address to attech to it:
Wonder of wonders, it worked. I was able to get into The Sims 4 with the new account. Thank you very much for that.
Except, now I will have to log in to that new account just to play The Sims, yes? What a pain. I signed back into my original account, and now EA won't even open. Is there anyway to fix that? Could I perhaps copy the new save folder to my old account to override the bad files?
Thanks for your help - you've done better than the EA staff.
@MsKayCeeSim52 The fact that the new account worked is a great sign. For the main account, try uninstalling the EA App with Revo Uninstaller (the free version is fine) and reinstalling it. If the App still doesn't work, that's its own issue, but if it does at least load properly, try again to play Sims 4.
If the game itself still won't load, with the App working, you can try a couple of troubleshooting steps in this thread:
https://answers.ea.com/t5/PC/CURRENT-ISSUE-Sims-4-already-running/m-p/13276380
specifically the steps move/restore location of Documents and and reset permissions sections. Much of that guide overlaps with this one, but not everything.
