See "communication failure due to routing device not available" errors when trying to view BACnet controllers or the objects they contain.
Continuum v1.74 and above.
The Cyberstation is unable to route to the desired device(s). This can occur due to changes in the network, network settings, or blocking software on the PC.
Check that the IP settings of all devices are configured so they can see each other. Specifically that the subnet mask configured for each device allows them to be seen on the same logical network.
Also see the following articles: