I know this is an old post but I was having this problem and I did a MIDI dump and BAM power cycled it and the computer seen it. I reinstalled driver like 3 times, tried different ports, computers, cables, ect and doing a MIDI dump worked.
I am trying to layer 4 guitar tracks, 2 hard left and right and 2 not so hard left and right. I have noticed when I double up on tracks and lets say they are both centered or both in the left or right they sound weird. They sound like there is a flange on them or some sort of modulation effect. I figured it might have to do with phase but even that seems odd. I am forced to pan only 2 tracks hard left and right or my guitar tracks sound very weird. Anyone know what is going on? I might just stick to modeling guitar amps with VST plugins instead as I did not have that issue using those. Thank you!