Do other devices connect to the ad hoc network? If not maybe something is wrong with the setup
- Reset the iOS device. Nothing will be lost
Reset iOS device: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Reboot the computer
- Reset network settings: Settings>General>Reset>Reset Network Settings
- Restore from backup. See:
- Restore to factory settings/new iOS device.