Check to make sure that the HDHomeRun has a good network connection, as indicated by the network LED on the device being solid green. For first/second generation HDHomeRun devices (HDHR-US, HDHR-T1-US, HDHR-EU), the network LED is the leftmost of the ones in the window. For HDHR3-US, HDHR3-CC, and HDHR4-2US, the network LED is the furthest left LED. For HDTC-2US, the network LED is the furthest left LED. For HDTC-2US, the network LED is at the bottom of the network port.
HDHomeRun Setup detected the PC is receiving UPnP discover announcement packets from the network, but is not receiving UPnP discovery response packets. This will cause problems with Windows Media Center and UPnP/DLNA applications.