Make sure you’re connecting directly to the computer and not through a USB hub of any type. Next, try deleting the H90 in H90 Control by clicking the X on the top right of the pedal icon that appears when you first start H90 Control. Then, click “Add Device” on the top right and see if Control detects the pedal. The last thing I would try is going into the Mac’s Audio/MIDI setup and removing the H90 there. Reconnect the pedal so the computer detects it once again and see if you can connect to Control.