Help! Error "To install the Sims 3 University Life you must already have the Sims 3 installed"

Please help! I've read through all the other posts I could find on this error and nothing seems to be working - I thought at first it was that I hadn't updated my game to the latest version but I just manually installed the patch and it says its updated to the most recent version but still comes up with the error message. I've tried putting it in a separate folder and using the .localized and nothing seems to be working. Any advice would be greatly appreciated

Hello,

There are actually two Applications folders in the Mac that your base game could be. Please try both to make sure that you are choosing the right folder during set up

Let us know if that works

Hi Dieneryn, 
Thanks, I tried both folders but its still not working :S. Is there anything else I could try?

I'm now also getting an error with my base game (which previously worked perfectly) saying that I need to insert the disc to play. Getting super frustrating, any help would be very much appreciated!!

Hello,

Sorry for the late response. May I know where you downloaded your base game from?