@IIISorryIWonIII You should be able to launch the game from the EA App now that you've launched it from Epic once. If not, uninstall and reinstall it through the EA App. You won't need to get rid of the add-ons from Epic either.
Before uninstalling, make a backup copy of the Sims 4 folder in Documents > Electronic Arts; this holds your saves and other user data. The folder shouldn't be removed during the uninstall process, but it's better to be safe than sorry.
Already did that, I can launch it via desktop shortcut but not EA launcher because it wants to open it thru Epic Games, also it launches with add-ons not working.
@IIISorryIWonIII Try clearing the EA App's cache:
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
and restarting your computer.
If you're sure you don't want the Epic-provided free packs, you could always unlink your accounts. (And you might need to uninstall and reinstall Sims 4, or clear the EA App's cache, afterwards too.) But relinking can be a problem, so it's best to be sure.
There's also a related problem that EA is investigating, or perhaps a bundle of issues:
The thread is kind of a catch-all, and I will admit I haven't read it all, but you could skim it and see if anything else in there helps you. (And please let me know if it does.) Otherwise, you could wait and see which problems EA fixes and if that solves your issue as well.
Hey, nothing helped also I have never managed to launch the game thru Epic Games
Even though I did download it from EA it still requires Epic Games Launcher
@IIISorryIWonIII Did you ever download Sims 4 through the Epic launcher, as opposed to downloading it through the EA App and trying to launch it through Epic? If not, please do so now.
If that 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/
