Motherboard post DB | Flash update has failed, but I have not updated bios

I own a server which resides locally in my house and I live alone. Last night the machine worked fine and this morning it would not boot. There was a black screen and code ‘db’ displayed on the board LED panel.

The code indicates ‘Flash update has failed’, yet I did not update the bios and cannot see a bios update utility on my machine. I booted on the backup bios and triggered recovery but would like to know what the cause might be.