Cause 12 of 12: The selected network is out of range
If you've set your phone to use a specific network, it can't get a network connection if the selected network is out of range.
Solution: Turn on automatic network selection.
1 Find "Network operators"
Slide your finger downwards starting from the top of the screen.
Press the settings icon.
Press More.
Press Mobile networks.
Press Network operators and your phone will search for networks.
2 Select network automatically
Press Search mode.
Press Automatic.
3 Select network manually
Press the required network.
4 Return to the home screen
Press the Home key to return to the home screen.