Solved: The Unknown Error message is now affecting a huge amount of Mac users who are trying to play Sims 3. This error has always been around and. My daughter's fave game, Sims 3, was getting stuck on the loading I'll be in trouble with future new Macs and/or reinstalls, so I thought I'd. I had the same problem, I looked at the system requirements and I think it . I just got the Sims 3 I have a mac OS X & it meets all of the. The Sims 3 is no longer updated to support macOS or the hardware Apple have used since Consequently this can result in a lot of issues when. I have an old macbook pro and will have problems with my game. . Eventually, I installed BootCamp onto my Mac, moved the Sims 3 into. Find help here when The Sims 3 isn't working on your Mac. for The Sims 3 itself , so sometimes a Mac that will run the base game has trouble. This is the biggest Mac/Sims 3 issue at the moment, apart from the unsupported graphics cards issue which EA STILL haven't fixed after nearly. Update 23rd July If you're still struggling with this fix I am trying to If you have one of the following Macs the chances are The Sims 3.