Sims 3 Seasons Game "No Disc Found"

[chelseadur]

I just bought The Sims 3 Plus Seasons tonight and I downloaded them both and they were fine. I got past the Seasons loading screen, and then I got to the screen with all of my families on it. A message popped up saying to insert the Sims 3 Seasons disk because it was not found, but my Seasons disk is in my MacBook. Help!!!!!