[Rpcemu] EtherRPCEm network interface is disabled/greyed-out?

Hi All,

Background:
* I'm trying the new release RPCEmu 0.9.2 with Networking on macOS
10.14.6 Mojave.
* By following the Networking guide at:
http://www.marutan.net/rpcemu/manual/network.html
* I merged the !Boot and !System from the EtherRPCEm folder
* It says: "In 'Interfaces' make sure EtherRPCEm is selected and click
the Configure... button."

Problem:
* I see the EtherRPCEm network interface, BUT it is
disabled/greyed-out? (attached screenshot)

Note: I've never before used Networking on RISC OS before, so please
assume I know nothing.

Any help appreciated!

Thanks,
matt