OMS Studio Setup will recognize a hot-plugged MIDI I/O interface only if you have previously declared it in OMS Studio Setup. (A hot-plugged interface is one that you have connected to a USB portafter your computer or OMS have already started up). MIDI interfaces that you have not previously declared in OMS Studio Setup cannot be hot-plugged. They will be recognized only after you quit and relaunch the OMS Studio Setup application. As a general rule, you should quit OMS Studio Setup before connecting any new MIDI I/O interfaces.