I have found the solution. The EA app was faulty and I needed to reinstall the EA app. Afterward I could repair the app and the game would run.
Piratprinsesse Are you trying to launch the game through Steam or via its desktop shortcut? If you haven't already, try through Steam and with the EA App already open and loaded fully.
If that doesn't help, please try playing in a clean user folder. Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop. When you launch the game, a clean folder will spawn with no content. (Your saves and other content will be intact in the folder you've moved but temporarily unread by the game.) Don't add anything to the new folder yet; just start a new save and see how it runs.
