Re: the game won't start/ something went wrong with repair
@andrejklimo16 If you want to run Sims 4, you'll need the EA App. Both the Steam and Epic versions require the App to be running in the background when the game is open. These and Origin/the EA App are the only legitimate sources of Sims 4.
For the issue itself, please uninstall Sims 4 and the EA App, reinstall the App, and install Sims 4 through whichever platform you want to use. If you own any content in Steam other than the base game, you'll need to run it through Steam to get access to that content. If you only own the base game, I'd suggest installing through the EA App just to keep things simpler, but a Steam install should also work.
Once you've reinstalled the game, let me know whether it works, and if not, what error you see when you try to launch it.