My MM DLNA server is setup correctly. I can browse and play music (mp3's only) using a variety of client devices and software. My TV is enabled in the UPnP/DLNA tab. From the log file it would appear that MM does not like being asked for the "Root directory" and serves up "null". Here is part of the log:
00016387 47.53071976  UPnP Server: Served item: Class: object.container.storageFolder, Title: Root directory
00016388 51.59572983  UPnP Server: OnAction: Browse
00016389 51.59576035  UPnP Server: Metadata to browse: (null)
My TV model is UN65J6300. The really strange bit is that I can use BubbleUPnP on my android phone to to browse the MM server and assign the TV as the renderer and the TV happily plays music. I am only serving music.