Most likely, it's the issue with the Epic Games Launcher and server that started about 5 hours ago and hasn't been fixed and no estimated time when it will be. I've been in the same situation as you. I've been trying for the past few hours to find a way to download the game from the EA site and play it without having to go via the Epic Games launcher but can't find a way. I've uninstalled and reinstalled Sims 4, unlinked Epic Games from my EA account, uninstalled and reinstalled Sims 4 again and still no go. Why won't it work from the EA launcher? I can't even play offline--it still wants me to log in to Epic Games, but I can't. Nobody can. https://status.epicgames.com/