I've done a lot of ship diagnostics over the years, and I do know for a fact that AF is an Armed Forces designation used by Bretonian-made consoles. The only thing I know about the other half of the designation is that supposedly BV is meant to signify boiling vessel? Not too sure about that, honestly.
The error code itself is.. quite interesting from the few cases I did see. What's essentially happened is that at some point during the ship's life, a bright individual designated the emergency backup powerplant as being the primary power source. The resulting blowout from an unexpectedly high power demand has now compromised the main reactor beyond acceptable parameters and the ship refuses to start because of it.
A good thing too, otherwise you'd be fairly crispy now as a result.
"Liberty or death."
-"Cobra"
☠ Transmission signal lost.
On indefinite hiatus because the current state of gameplay sucks - ping me over discord if replies are needed