LinuxCNC computer not connected to network

I am attempting to work on the Debian machine with LinuxCNC installed, but booting LinuxCNC fails with the error message:

ERROR: Could not retrieve mac address

Not super familiar with Linux and I haven’t been able to troubleshoot the connection successfully. Any tips for getting it back online?

It is not supposed to be connected to the network, as it is doing realtime control of heavy equipment, and there is no function it does that needs the internet.

There is a Windows PC right beside it that has the full VCarve Makerspace Edition on it that will connect to the internet.