restarting the computer, and cycling the power on the FF400 was no use. Other applications can still see the Fireface ... including Live 7.14
here's a comparison with Live 7.14

logs are available...
I have zipped up the user-data folder (database, preferences, unlock) for forensics
I will probably want to try a total reinstall tomorrow to try and regain the application. That's enough for tonight though.