Symptom: Apogee Maestro will not properly recognize Duet 2 (USB) if Mac user is logged into a Guest Account. Maestro simply says “No Apogee Systems Found”.
Resolution: Confirm you have latest Duet software installed (you can download here), go to Apple Menu>System Preferences>Show All>System Accounts>My Account view>Set User Name to Admin, restart the Mac and Maestro will now launch successfully.