How have you setup the network share on the QNAP? Is this via samba? If so, I would try entering smb://192.168.50.205/MyMusic as the network share location.
Sorry I made a typo in my response. IP address should be 192.168.50.205. I see in the screenshot you copied from me, so first try to make that correction.
Other than that, are you able to access the network share from any other machine? Just trying to figure out if the issue is on the Nucleus side or the NAS side.