iPhone 4: Unable to use FaceTime after porting your number or installing a carrier settings update
To resolve this issue:
- Use iTunes to update to the latest version of iOS for your iPhone.
- Disable FaceTime in Settings > Phone and then turn it on again. Do this by sliding the slider off and then on.
- Reset All Settings under Settings > General > Reset.
Related posts:
- Unable to use Wi-Fi or Bluetooth with iPhone or iPod touch because there’s no address listed for the device
- iPhone 4: Using FaceTime behind a firewall
- Installing iPhone 2.2 Software Update on iPod touch
- iOS 4: About over-the-air carrier settings updates
- About iPhone carrier settings updates in iTunes