Disk authorization failed Sims 3

So iv got a bit of an issue. A couple days back i deceded that i wanted to try out the sims 3, yet being on a macbook air, i was fourced to buy the download game code that would let be play the game. Everything ran smoothly with that transaction, buying it from amazon and then getting it onto origins, yet after all of the downloads had been completed and i was at the home screan of the sims three, it kept prompting me to insert the disk because it needed to authenticate the game, even though it was a digital download. Can anyone give me any advice to solve this problem? if so it would be most gratifying,

thanks, Just4dalolz.