Try charging your phone to its max and try again this. This should work,do do not turn on your phone until it shows that it is 100% charged Reboot. Reboot your phone and disable ultra saveUltra STAMINA mode, everything should be fine If ur.
If your battery is less than 15% ultra save, Ultra STAMINA mode dodoes not allow flash ,camera camera location, 4G which requires maximum power and drain the battery
1.Charge your battery to max 2.Reboot it 3.See the magic
- Charge your battery to max
- Reboot it
- See the magic