Most BlackBerry KEYone devices have a locked bootloader . Unlike other Android phones, you cannot easily flash custom kernels or modified system images unless you are using a specific, signed Autoloader provided by BlackBerry (or a verified community "repack" that maintains signature integrity). How to Flash a Clean Autoloader:
If the device vibrates and shows the BlackBerry logo, release the buttons. Step 2: Verifying Your "Repack" or Autoloader blackberry keyone stuck in bootloader menu repack
Before diving into complex software fixes, try to force the device to boot normally. Disconnect the KEYone from any power source or computer. Most BlackBerry KEYone devices have a locked bootloader
If the battery is below 20%, the bootloader may refuse to flash the system partitions. Let it sit on the bootloader screen while plugged into a wall charger for an hour before trying again. Step 2: Verifying Your "Repack" or Autoloader Before