Thanks Andrew for your replay! This is helping back-fill my huge knowledge gap using this tool.
While I understand your reply on only being able to see a couple tracks and my experience validates what you are saying, I am having problems getting the process to repeat itself right now. Now I cannot Push through the Renderer anymore or Pull through the server as JimH tried to explain. From using FooBar I understand the basic concept of the Media Manager for the music library and then the UPnP Controller plugin that handles the communication with a player (in my case the Marantz). That said there is something else going on with the JRiver design that I think escapes my understanding of how this works and why I'm having so many problems with what on the surface is not that complicated. When I look at the five servers that are running though, I confess I am not grasping why it needs to be this complicated: 1) PC Library Server 2) Device Discovery Server 3) DLNA Renderer 4) DLNA Server 5) DLNA Subscription Yikes!
To answer your question, I am trying to play a standard mp3 track. Regarding your 2nd question on "MC Network DLNA Server Settings", I am not sure what you are asking here. So, I have attached 4 different pictures (note - big pics you might need to use side and down bar to see the whole thing) of what I'm seeing and hopefully one of these provides the info you need to guide me.
And, to reiterate, the Marantz seems to be connected. When I try to play a track this morning the Marantz lights up and it "sees" the track transfers and even displays the name. But it stays at 00:00 on the Marantz and will not start playing (like it is waiting for another command). That is still my current status. I also tried using my Sony Streaming interface box that I use successfully with Windows Media, Foobar and Twonky and get an error with that: JRiver says "There was a problem controlling the selected DLNA device. Double check your device, server and network settings".
One other item: when I first set up JRiver i ended up with an icon in my System Tray. Today that is not showing up. How does this get turned on and off? (Update: I figured out this happens in the Tools pull down)
I spent about 4 hours reading various posts, rereading wikis, and going through all the settings. I'm running out of steam to get something I want to buy to work.................
The only reason I'm putting so much effort in is the other players all have their issues and JRiver is touted as "the best" from many sources.......