I have developed an app that enabled push notification. It is available in AppStore. After installing the application on my device it shows Alert for enabling push notificat
1.Delete your app from the device.
2.Turn the device off completely and turn it back on.
3.Go to Settings > General > Date & Time and set the date ahead a day or more.
4.Turn the device off completely again and turn it back on.
for reference: https://developer.apple.com/library/ios/technotes/tn2265/_index.html