Ultra STAMINA mode bug on Sony Xperia Z3?
Try charging your phone to its max and try again. This should work, do not turn on your phone until it shows that it is 100% charged. Reboot your phone and disable Ultra STAMINA mode, everything should be fine.

If your battery is less than 15%, Ultra STAMINA mode does not allow flash, camera location, 4G which requires maximum power and drain the battery.


Charge your battery to max
Reboot it
See the magic