Upgrade problem

Hello Immortal,

first power off your device by pressing the power button for 10 seconds. When your device is off, press the power button again to turn it on, but keep holding the power button. When you see the Oukitel C15 Pro logo, release the power button immediately and press the volume down button. You shoud see Safe mode on the bottom, left corner, that's your cue to release the volume down button. 

The Safe mode starts your device without any third party apps or services, allowing you to reset your phone for example.

Have a nice day!

Isabel