This is the error message!
It's in Norwegian but it translates to:
A problem(/an issue) occured during the validation of your ownership of the game. Please confirm your game registration key and reinstall the game.
@maddew123 The finalizing issue can usually be fixed by repairing the game: open your Origin game library, right-click on the Sims 3 icon, and select Repair. If that doesn't help, run the Origin reset tool and repair again.
https://help.ea.com/en-us/help/origin/origin/how-to-reset-origin-on-mac/
I really do think the underlying issue here is that you don't own the packs you're trying to play. Again, there's no mechanism to validate ownership of EA Play content in macOS, because that content isn't supposed to work in macOS. If repairing doesn't help, and you want to play on your Mac, try playing only the base game: uninstall the entire thing through Origin, run the Origin reset tool (again), and download the base game without the packs.
