An Autoloader is a that contains:

You flashed the wrong firmware (e.g., BBB100-2 firmware on a BBB100-1). You need to find the exact correct PRD Autoloader. If no correct file exists, the device may be permanently bricked.

Make sure your KEYone has at least 50% battery life to prevent it from shutting down mid-flash.

No. The Autoloader locks the bootloader back to stock. However, you can flash an old Autoloader (Android 7.1.1) and then use the SunShine app to unlock it. The Autoloader is a prerequisite, not the unlock tool.

Download the (ADB and Fastboot drivers) to ensure your computer recognizes fastboot commands. Step 2: Download the Correct Autoloader File

The last authentic BlackBerry, Liam had always called it. Not that slab of glass and forgotten notifications that TCL shat out later, but the KeyOne. The one with the actual keyboard, the dimpled back, the heft of a phone that remembered BBM and blinking red LEDs.