We are starting to get more cases on this interesting issue when using a Mac as a license server. Normally, you would need to use the built-in Ethernet card to generate a license file but you may actually now need to use the 802.11n Wi-Fi wireless networking card instead if you get this error:
Server line says #, hostid is #
I have seen this error before affecting Mac Mini's but I have now seen this problem on an iMac running Mac OS 10.8 (Mountain Lion). NOTE: The server software is not supported yet on the latest Mac operating system.
Apple is not including a built-in Ethernet card for some of their hardware. It is an interesting co-incidence.
Thanks to Eric Kunzendorf for confirming this solution.