1) Verify that Ethernet is selected in the AppleTalk Control Panel. In some cases, performing a clean install of the Mac OS has been required to reestablish communication with the Ethernet port.2) Verify that ProControl is connected via Ethernet with either the red crossover cable (main direct to Mac) or standard cable (main or main+faders connected to a Hub).3) Run ethernet tests in secondary utilities pages. Hold down Shift + Option + F4 on each fader section. Press ETHERNET. Run INTERNAL then EXTERNAL (you need the loop back plug for the EXTERNAL test). You should see only one number scrolling when running INTERNAL test and two when running EXTERNAL. In EXTERNAL, both numbers should be incrementing at the same rate, but not displaying equal values.