Re: Sims 4 Not Launching - "install an app to open this link" error

@mooseyemma  Try uninstalling and reinstalling only the EA App with Revo Uninstaller (the free version is fine).

If that doesn't help, please let me know whether you've ever claimed any Sims 4 content from Steam or Epic Games.  This could be the problem even if you never used either launcher to run the game.

It would also be helpful to know exactly what the error says.  If you can't grab a screenshot, you might be able to record a short video and grab the appropriate frame.