Originariamente inviato da
esatch
fai questo, punto per punto, avevo lo stesso problema e ho risolto subito SOLO con questa procedura (da en.miui)
1. Download 7.2.16 Global Developer ROM - h**p://bigota.d.miui.com/7.2.16/miui_HMNote4XGlobal_7.2.16_e6eed016d8_6.0.zip
2. Install the ROM via the Updater app.
3. Reset to Factory Settings
4. While it boots, remove all SIM cards from the phone
5. On bootup, do not select a WiFi network to join. Skip this step.
6. Skip any and all steps that require a login. You shouldn't be able to anyways since you don't have WiFi or Cellular Data.
7. Once at the home screen, turn on your WiFi.
8. Unlock Developer options.
9. In Developer options, turn on OEM Unlock and USB Debugging
10. In Developer options, bind your account to your device. At this point, you should be prompted to login to your Mi account. Go ahead and do so. At this point, you may or may not have received an error binding your account. But we can ignore this message.
11. Turn off the phone.
12. Boot the phone into fastboot mode (Volume Down + Power)
13. Plug the phone in to your PC and run it through MiFlash to unlock your bootloader.