@Mafrican17 It sounds like you've installed the 32-bit version of Sims 3. I can help you get around the unknown error, but you may want to play the 64-bit version instead, in which case troubleshooting this error, which doesn't occur in 64-bit, would be a waste of time. If you do want to play in 32-bit, please post the full specs of your Mac: everything under About This Mac except for the serial number.
You should have the 64-bit version of Sims 3 in your Origin account, but let me know if you don't. When both versions are available, they show as separate entries:
My 32-bit version is grayed out because my computer can't run it. At any rate, if you don't see this second version, specifically the one that says 64-bit on it, contact EA customer support and ask that the "entitlements," as they're called, for the base game and any packs you own be added to your account. This is simple for a support rep to do once they understand the issue.
