Re: Sims 4 won't launch in the EA app 20/01/2024
@emma_g345 Among the many things you tried, did you ever move the entire Sims 4 user folder to the desktop? Moving the Mods folder inside was a good idea, but it's possible for the folder to contain other corrupt files as well.
If this doesn't or didn't help, please run a dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/
And let me know what antivirus you use. I've seen two reports recently that Surfshark is causing problems with Sims 4, but a few others block the game from time to time as well.