I am a new user of Roon and set everything up OK. Roon seems to have detected everything in my library initially. I am now adding some new albums but Roon does not add them to its library. I have tried restarting the Roon core and forcing a rescan.
Roon core is running on Mac Mini and music library is on a NAS drive. The files are in FLAC and M4A format and play OK outside of Roon. Permissions don’t seem to be a problem as the user (“roon”) has full read/write access.
I figured out the problem. Roon connects to the NAS using an account called “roon” which has read/write access (according to Synology DSM). When I copied a new album onto the NAS I connected with a different account (also has read/write access).
I noticed that Roon could not “see” the new album when I tried to map another drive to Roon. So I removed the shares and re-added as the same user. Now it works!
Must be something weird going on with permissions - even though both accounts have full access.