Net3 Show Control Gateway stuck on "Network Stack Starting"

We just received a Net3 Show Control Gateway bought second hand, and it won't start.  It's stuck at "network stack starting."

I see through the network router's configuration that some device with a MAC address very similar to another Show Control Gateway has been assigned an IP address, and I can ping the device at that IP address, so I think it's kind of working, but Concert doesn't see the gateway.

Is this a common issue with an easy fix, or is this gateway busted?