Anybody used Cover Scout 3?

I love my SONOS products, but am having a tough time with the album art showing upo when I access my music collection that is on my attached NAS (WD My Book Live). Upon the suggestion of Sonos customer support I went and bought a third party software called "Cover Scout 3". It looks like exactly what I need, but despite setting it up as instructed to access my NAS, it id not "seeing it" and linking or updating the cover art.

Any suggestions?