Re: Downgrade from El Captain to Mavericks?
Okay, please check this thread with more info about this issue and how to solve it: http://answers.ea.com/t5/The-Sims-Mac/CURRENT-ISSUE-The-Sims-3-Disc-Authorisation-No-Disc-Errors/m-p/4882518
Closing this thread to avoid duplicates.
