Hello QNAP 5.x and roon users and @crieke
If you use your share path, e.g. \QNAP-TS364\Musicfiles to your Music folder root on the NAS it does not work and shows now errors during connection, but no music files.
So far so bad.
I found a solution to get rid of the the access problem to local music files on the QNAP NAS with QTS 5.0.0.1986 and older:
If you use the Localhost IP 127.0.0.1 and not the Sharepath it works and roon scans and plays all files!
\127.0.0.1\Musicfiles
Enjoy the music again 
BTW
The tip for this workaround came from my good friend Bernd who is a Linux Super-Guru, he work with embedded and PC Linux Systems and his gome if full with Linux devices. But he has no roon jet. He still uses the good old LMS Logitech Media Server ex. Slimserver/.
I am telling often to switch to roon, but he does not like the license fee.
Maybe roon gives him a foc license for this fix? 