well, are you using game center in your app? If you aren’t then get rid of that switch and you should be fine.
I looked up on the Apple Developer Forums and there is a thread that mentions some entitlement issues on 10.8.2 and a way to work around it. I don’t know your platform but just in case something in the thread might help: https://devforums.apple.com/thread/168811?tstart=0 (Apple ID required)
Thanks for your reply.
But Game center under sandbox condition is working just fine.
The problem is that I have no problem testing game center but Apple keep rejecting with the same reason “Not properly sandboxed”.
sorry for bump this topic, but I thought that for someone this maybe useful.
HOW TO FIX THIS PROBLEM:
You can add to your entitlements to fix this:
com.apple.developer.game-center
It’s strange that Xcode doesn’t provide this as an entitlement option, but your app will be rejected during the review process if you don’t include this.