When trying to restore a backup, a message might say that your iCloud backup requires an iOS update, or your iTunes backup can't be restored because the software is too old.
If you're asked to update your software in the setup assistant, follow the steps to update your software. If you aren't asked to update, you need to follow these steps:
Set up, update, and erase your device
- In iTunes, or from the Apps & Data screen on your iPhone, tap Set Up as New instead of Restore from Backup. If you already tapped Restore from Backup, tap Back to return to the Set Up screen.
- Follow the remaining steps. For now, you can skip the steps for Apple ID, Touch ID, and passcode.
- Once the set up is complete, update your device to the latest version of iOS.
- Let the update finish, and wait for your device to restart.
- Erase your iOS device: Tap Settings > General > Reset > Erase All Content and Settings. After your device is erased, it restarts and you'll see the Hello screen in the Setup Assistant.
Now you should be able to set up your device again, and select a backup to restore from.