@jdowney83
Have you got an older 'official' NA map on your Kenwood at present and is it also a DNX9990HD? If so, you should have both unl and gma files specific to your UID already loaded with that old map. The 2013.40 map worked in EuroDriver's own unit and his wife's too using the 'official' unl & gma files from 2013.20 specific only for his unit ID.

The only concern might be that the fresh map upload will 'wipe' not only the old map but also the gma & unl files however it shouldn't 'brick' the unit.