True for: Fire Kindle 2015(?) No home button or "Kindle" on face (if that helps)
In this instance: I cleared cache, factory reset, before booting saw the "Apply ABD Update" but my brain really just saw "Update" so I clicked it thinking, "Hmm i did just factory reset so, I should probably reUpdate" clicked it realised I shouldn't have, and googled "undo ABD Update Fire kinda...." Redirect here read a few comments until I saw the "Power Button plus up volume and hold for 10 + seconds" method (which is how I got to the bios mrrnu to begin with) but it didn't work. After a few tries I tried other combinations of button holds until yellow triangle with an exclamation popped up on screen but wouldn't go anywhere else. Eventually I figured out that if you click power plus volume up 2 times in quick succession that pops up and the same to make it go away. Pointless discovery...I then put the tablet down and came back to this thread and as I kept reading the tablet lit up on its own with a message saying, "ABD update timed out, you can try again in a few minutes" and then returned to the main Bios menu by itself. . .lol so, there it is. It fixes itself, apparently, if you just chill tfo long enough to let it. Laters on tha menjay, Joben.