I have the same problem.
My configuration: Volumio1.55 running on a Raspberry Pi B+/HiFiBerry DAC+
My music library is stored on a Windows 7 box on my network running Windows Media Server (WMS) to handle the DLNA.
I flash the RPiB+ memory card with Volumio system and configure the network. Volumio then shows up in the WMS’s on the Windows box – all of them on the network in fact – as a media device with the “Play to” option. I can stream music to it from my Windows boxes on my network. The sound is great and all is well. Looks like UpMpd and the hardware as well my network configuration all works fine.
But when I tell Volumio about the location of my music library using the Library page of its webGUI the “Connecting” message with the two tail-chasing arrows grays out the Volumio Library setup page, and nothing works from that point on.
The “Play to” option on WMS on every windows box disappears, too. It’s like the UpMpd server is disabled.
After that I can only reflash and reconfigure to do anything. It’s very frustrating.
After weeks of playing with this off and on, I’m no longer sure what I might hope to do with Volumio. All the enthusiasm on the Volumio Get Started page here https://volumio.org/get-started now rings hollow.
I thought I’d be able to go to the Volumio webGUI and play tunes and playlists from the server. I thought I’d be able to do that from any any browser-equipped computer or smartphone on the network.
In other words, I was hoping that Volumio would act as a DLNA Digital Media (DM) Player to pull content from DLNA DM Servers on my network and play it, not just as a DM Renderer – like UpMpd – to receive content from other DM Players. (Definitions here: http://en.wikipedia.org/wiki/Digital_Living_Network_Alliance.)
At this point that’s just not happening.