Mezzmo stopped communicating with router

[ComputerPerson]

Mezzmo was working fine streaming from Dell desktop through a MoFI WiFi router with Panasonic TVs but suddenly stopped communicating with the WiFi router.

TV's show up on router & TVs can access internet via router, but there is no link between Mezzmo and TVs & TVs give error "can't find DLNA server.

The computer is wired to the router, and the computer can find and access the router, just not Mezzmo.

So I expect there is a problem between the router and Mezzmo.

I have recycled the router and computer & TV's and problem persists.

I cannot see Windows Media server on the TVs either, if I turn it on.

How do I go about fixing this problem? IS it a network configuration?

Windows 8 Pro 64-bit with Media Center

Thanks!