Hi
we have the Tascam US122MKII as well as the US144MKII. All the Tascam USB audio I/O used to work normally with OSX Sierra 10.12, but not on the OSX 10.12.1 beta update.. Most unfortunatly..The lights of the units go on, then out, no response, somehow it seems they are 'bricked' . About this Mac wont show the Tascams in USB devices, the USB cables are ok, the units are ok (they do work on a ancient iMac with 10.5.8) indeed the Soundflower could be an issue, we erased Soundflower and somehow also with that the Tascam Drivers.. Reinstalling the Tascam drivers and firmware only ends up in the notification in Tascam Control Panel: Device not recognised. Somehow it seems that OSX cannot connect to Tascam via USB.
The Tascam drivers can be found and erased at the following locations:
/library/preferences/audio/
/library/audio/midi drivers/
/library/extentions/
/library/audio/plugins/hal/
erase all