From what I can tell, I need to use the redeem code link found in the iOS dev center to update 10.10 to dp2. However, when I get to the app store, it notifies me that the code has already been redeemed. Is there another way to update or get my code working? I'm currently running the first preview of Yosemite. I didn't have any problems when I followed the same step that time. FIXED. The appstore update panel wasn't showing an update, so I assumed I needed to go through the dev center. There's an update appearing now.