Hi @roymacdonald, confirmed that it runs on current master branch on OS X10.10.3.
I guess the old branch that I was using has some unupdated libraries or something. It's not that uncommon for MIDI to generate audio related erros, and this one relates to USB connection of interfaces (which... kind makes sense?).
I like 10.10, just gonna do a minor update from 10.10.3 to 10.10.5, works well in here.
Thanks a lot for the help, that solves both my problem and the (proven to be unexistent) community problem!