Re: The Sims 3 Katy Perry Showtime
to be sure: You bought two games: Showtime and Katy Perry Sweet Treats (which is a stuff pack) but you were only able to register showtime or did you buy the Katy Perry Edition of Showtime ?
If it's the first: What error are you getting trying to register the stuff pack
If you bought the KP Showtime, the game itself is the same. Only difference is that the Katy Perry Edition comes with extra content. You should have an extra 16 digit code with it, which you redeem here: https://store.thesims3.com/myAccount.html where it says redeem a code.
Then you can download the extra content from your purchase history: https://store.thesims3.com/purchaseHistory.html
