Forum Discussion
@Isiaczek2 The last few versions of mac OS, including Mojave, will fail to authenticate Sims 3 discs. The solution is to manually uninstall your newest pack by release date (Into the Future for you) and reinstall the digital version via Origin. Then you won't need a disc to play.
https://bluebellflora.com/manually-uninstalling-an-expansion-or-stuff-pack-in-the-sims-3-for-mac/
If you never registered your game, you can still do so now. The codes are the same ones you used to install the game. If you've lost or thrown away the CD case inserts that had the codes printed on them, you can find the codes via Terminal. Be sure to do ths before you uninstall Into the Future.
https://bluebellflora.com/finding-your-serial-key-using-terminal/
Edit: I've moved your post to the dedicated Sims/mac section. Please let us know if you still need help.