Re: The Sims 4 game data is missing or damaged.

@BarbaraMdn  I'd like to find out whether the problem is the game data or your current Windows account.  Please try playing in a new admin Windows account.  Make it local, as in, don't link it with your Microsoft account.  You'll be able to open the EA App and (try to) launch Sims 4 without reinstalling anything, but your saves and other user content won't be available.  That can be addressed later; for now, just let me know whether this works.

@BarbaraMdn  Here you go:

https://support.microsoft.com/en-us/windows/create-a-local-user-or-administrator-account-in-windows-20de74e0-ac7f-3502-a866-32915af2a34d

@BarbaraMdn  Restart your computer, then choose to login to the other account.  You should see the accounts listed on the login screen.

@puzzlezaddict I thought I needed to do that too but I never got that option on my login screen.

@BarbaraMdn  Can you switch users from the ctrl-alt-delete screen?  If not, do you still see the other user you created listed under Accounts?

@BarbaraMdn  That means the problem is something about your main account, whether borked permissions or another error.  In your main account, please search in Windows for "command prompt," launch it, and enter this command:

reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders" /v "Personal"

Post the result here.  This is partially to confirm that the user Documents folder is in an appropriate location and partially so that I can be more specific about the next troubleshooting steps.  That assumes you want to fix your main account, however.  If not, you could of course just play in the new account and move over any other files you wanted to keep.  It's your choice.