I use a ULN-2 with a Firewire to Thunderbolt Adapter on my MacBook Pro with OS X 10.9.1.
When I plug the ULN everything works fine and I can select it in the System Preferences in Ableton Live.
If I start the MIO Console 5.6.04.215 it immediately shuts down again and the error message says Application quit unexpectedly.
If I disconnect the ULN-2 I can open the MIO Console with no problems. But if I plug the ULN-2 in while MIO is open the same crash happens immediately.
I already reinstalled the app and also deleted the MioConsole Preferences in the User Library with no success.