Kingo is different from King
If Kingo will does not works,
probably I will have the proof that your phone has the locked bootloader.
Steps to unlock the bootloader :
1) Tap on "Developer options"
2) Tap on "OEM unlocking" and tap on "USB debugging".
3) Connect your phone to your pc with USB cable.
4) download & install "adb-setup-1.4.2.exe" from the next links :
5) Type "Y" when you install "adb-setup-1.4.2.exe".
6) Open cmd prompt ... and type the next command :
adb reboot bootloader (and press enter)
7) Now type the next command :
fastboot oem unlock (and press enter)
8) Press VOLUME UP (into your phone) to confirm to unlock the bootloader.
You will see in the CMD prompt the next messages :
"Start unlock flow" ... and when it will be finished ... you will see "OKAY".
9) To reboot your phone type the next command :
fastboot reboot (and press enter)
10) To verify if everything worked out,
reboot once again your phone into FASTBOOT mode,
and type the next command :
fastboot getvar all (and press enter)
11) If you will see "bootloader unlocked : yes" everything worked out.
NOW try once again the new version of King Root :
If the first time it will fails, try it different times.
If Kingo will does not works,
probably I will have the proof that your phone has the locked bootloader.
Steps to unlock the bootloader :
1) Tap on "Developer options"
2) Tap on "OEM unlocking" and tap on "USB debugging".
3) Connect your phone to your pc with USB cable.
4) download & install "adb-setup-1.4.2.exe" from the next links :
5) Type "Y" when you install "adb-setup-1.4.2.exe".
6) Open cmd prompt ... and type the next command :
adb reboot bootloader (and press enter)
7) Now type the next command :
fastboot oem unlock (and press enter)
8) Press VOLUME UP (into your phone) to confirm to unlock the bootloader.
You will see in the CMD prompt the next messages :
"Start unlock flow" ... and when it will be finished ... you will see "OKAY".
9) To reboot your phone type the next command :
fastboot reboot (and press enter)
10) To verify if everything worked out,
reboot once again your phone into FASTBOOT mode,
and type the next command :
fastboot getvar all (and press enter)
11) If you will see "bootloader unlocked : yes" everything worked out.
NOW try once again the new version of King Root :
If the first time it will fails, try it different times.