windows 7 client can't connect to serviio (more in post)

Sorre for the title but i can't figure out better.

This is the situation:
serviio server on a windows 7 - 32 bit connected by wi-fi

Clients:
A) bubbleupnp on galaxy s4 and a tablet connected by wi-fi
B) vlc on a windows 7 64bit wired connected

From A i can connect and see everything.
From B (tried wmp too but i know it isn't working):
- i can connect to my andoid devices running bubblepnp (but they are just clients for serviio);
- i can see serviio server but cannot connect, can't see anything, only the server name.

Any ideas why?

Thanks