@cjones13 The workarounds that you need are creating an alias for any packs that don't already have them, copying files from the folder of one pack to another, and editing your .sgr files.
Depending on your computer's specs and which packs you have installed, you may or may not need to do all three steps. If you could post this information, we could help you get the game running on your mac.
2.9 GHz Intel Core i5
Memory: 8gb 2133mhz
Intel Iris Graphics 550 1536 MB
The only game I installed was the main game. When I launch it I don't even get the Sims 3 plumbob, I only get the Unknown Error message.
@cjones13 Since you can't even run the base game, you'll need to edit the .sgr files. But there's someone who can help you with that, if you want. Bluebellflora is great with this kind of thing, and she's around right now, if you're interested. Just post here:
@OceanGRose Since there are so many different issues with Sims 3 in mac OS, I'm not sure which problem you're referring to. But the video is probably this one, which shows how to move files from certain incompletely installed packs into the folder of your newest pack by release date:
This is only one of the fixes for the unknown error. If you've installed any of Ambitions, Late Night, Fast Lane, and Outdoor Living, and at least one of those four packs is not your newest (by the date EA released it), then you'll need to apply the fix in the video. (If, on the other hand, you only installed one of those packs, and it is your newest, then you could skip that step.)
These four packs usually don't have their own aliases in Applications, alongside the alias for the base game, so you'd need to create one for each of them as well. But that's simple:
If these steps don't help you, the problem may be your graphics card—some are not supported by TS3. In that case, you'd need to edit the game's .sgr files to force it to recognize your card. If you'd like help with this, or you're not sure whether it's necessary, please list your computer's specs here, as described in this post:
Solution for unknown error for The sims 3 i found here : https://www.youtube.com/watch?v=kDdtZIuu89I
July - last edited July
That video only describes the fix for one of the six different causes of the unknown error message, and doesn't cover all the details about that one approach, either. Luckily, Bluebellflora wrote a comprehensive guide to installing Sims 3 in macOS. It's in her master help thread pinned to the top of this forum, or you can find the guide in this post: