Server not showing NDX2/Mac mini - ? Java issue

[simoncn]

From the information you have provided, this seems like a network UPnP multicast discovery problem. You can find more information about this on the Troubleshooting page.

The first thing to try is power off all your network devices and power them on in the order described on the page.

If this doesn't help, look at your router settings. If IGMP snooping is enabled, you should disable it if you can.