Assuming you've ruled out any configuration issues, this sounds like another instance of:
http://www.ventismedia.com/mantis/view.php?id=12384

So far we haven't been able to replicate this or get any useful debug logs that tell us why this might be occurring. Can you:
a) confirm whether MMA can access _other_ UPnP servers?
b) generate an MMA debug log and share the log ID in this thread?

Note: rebooting your android device should solve the problem, but please provide us the answers to the above before doing so.

Thanks.

-Rusty

Is MMA on the same network as MMW (not on guest wifi for example) and is your device allowed in the MMW Media Server settings?

Hello,

I'm not sure if this is a MWW or a MMA Problem
Im using the above mentioned combination as recomended with a XPERIA Z1 Compact running Android 4.4.4
In MMW there are Media Monkey Library Server and Media Monkey Server running and active
MMA doesn't find any Server for sync.
Media Monkey Server is found by other DNA appliction (tested with Pioneer VX922)
Usualy I see there both Servers.
Do you have any idea how to fix it

Kind Regards

RogerK