If you find you can access only channels 1-32 and 33-64 are missing, make sure the Slave iLive Port B ACE Redundant Link option is turned ON.
To do this go to the Surface MIXRACK SETUP / Mixer Pref / Port A/B Setup screen, or Editor Setup / Mixer Preferences menu.
This ensures that all 64 channels are available at the ACE sockets.
If Redundant Link is turned OFF then ACE Link 1 receives channels 1-32 and Link 2 receives channels 33-64.
This setting is used when connecting two xDR-16 expanders.