If the menu options aren't responding, select "Turn off the device" from the menu. Let it charge on a wall outlet undisturbed for several hours before trying to power it on normally. Advanced Troubleshooting
In the specific case of the KeyOne, the most common culprit is a failed OTA update. As the device ages, the internal storage (eMMC) can degrade, leading to write errors during the update process. Consequently, the device finds itself in a limbo state: the integrity check fails, the bootloader refuses to hand off control to the Android OS, and the user is left staring at a static screen. blackberry keyone stuck in bootloader menu