I mean that I'm not using bluetooth (can't use it actually because I'm on PC), and I'm not using MIDI cables. All I have is a USB plugged in. Shouldn't I then be able to choose in Control's settings to attach to one of my midi devices? it does work this way doesn't it? because it absolutely doesn't for me. I wanted to be able to control my H9 with my midi devices. But Control just keeps crashing. Midi was one of the big things for me….
Do you have a DAW or anything else trying to connect to these same MIDI devices? If so, then that other software application is going to lock up the MIDI port and make it impossible for H9 Control to open it and connect to it. I've heard that Microsoft fixed this in Windows 10 by allowing multiple devices to connect to the same MIDI device. On Mac multiple devices have always been able to connect to the same MIDI device. Further up in this thread people helpfully explained the various solutions that they have found to work around this problem in earlier versions of Windows.