UIM 8.51 - but valid for any UIM release
cdm: 6.30 - but valid for any cdm probe release as well as any local monitoring probe that needs to provide additional information to the probe's Configure GUI (like the processes probe)
Firewall between the managing hub and the robot was blocking access to the cdm probe on port 48008. Error messages similar to the following can be found in the hub probe's log file at loglevel 3 after opening the Configure GUI for the cdm probe on the remote robot:
Feb 20 10:15:26:425  hub: nimSession - failed to connect session to <robot IP address>:48008, error code 10060
Feb 20 10:15:26:425  hub: TSESS-P-583-83 [<managing hub name> could not connect locally to /<domain>/<hub name>/<remote robot name>/cdm (<remote robot IP address>/48008)
Open a range of ports in the firewall between the remote hub and the robots it is managing to allow the hub direct access to the probes installed on the managed robots.