Hello @Peter_Dawson
Peter, thank you for documenting that so carefully. Two things, and the first one may change what you want to do at all.
Why 2.71 failed on the Mac mini and now works
That was a fault on our side, not on yours, and it is already fixed. Build 1680 of 2.71 stopped Roon Server from starting on macOS 12 and 13 specifically. Your Mac mini is a 2014 Intel model on Monterey 12.7.6, so it was squarely affected. When you rolled back to 2.64 and later came forward again, you landed on build 1683, which carries the hotfix. That is the whole explanation for “why does it work now when it didn’t before”. Nothing you did differently, and nothing wrong with the machine.
The tracking thread is here if you want to see it: RoonServer 2.71 crashing on startup on Intel Mac Mini, hotfix released
So you can keep using the Mac mini for as long as you like. Monterey 12.7.6 meets our requirement of macOS 12 or later, your library is working there now, and there is no deadline hanging over you. Moving to the MacBook Air is a choice, not a repair. If you would rather stop here, that is a perfectly good outcome and you can leave the MacBook Air as a remote.
If you do still want the MacBook Air as your server
Your screenshots answer why it fails, and the answer is not Synology and not SMB.
Look at your first screenshot. Roon is showing Macintosh HD > Volumes > music and reporting it empty. So Roon can see the folder and cannot see inside it. That is the same failure as the “Unauthorised” you get when adding the share directly, and it is why launching Roon Server from Terminal works: a process started from Terminal inherits Terminal’s permissions, whereas Roon Server started normally has to hold its own. Our macOS guidance describes the symptom exactly, that Roon Server “may fail silently” when macOS blocks this.
Roon Server is a separate binary inside the Roon app, so it has to be added by hand:
- Open System Settings → Privacy & Security → Full Disk Access.
- Click + and unlock with your password or Touch ID.
- Go to Applications, right-click Roon, choose Show Package Contents, then Contents → MacOS, and select RoonServer. This is the same file you have been launching from Terminal.
- Make sure its switch is on.
- In the same Privacy & Security section, open Local Network and confirm both Roon and RoonServer are enabled.
- Quit Roon completely, confirm in Activity Monitor that no Roon processes remain, then start Roon normally rather than from Terminal.
One thing to check before judging the result. Please confirm in Finder that music is actually mounted at that moment. If it is not, /Volumes/music will be an empty leftover folder and Roon will correctly report it as empty whatever the permissions are. macOS leaves that stub behind after an unclean disconnect and it looks identical to a mounted volume in Roon’s browser.
Housekeeping, once access works. Your Storage list holds three entries: a disabled “Music Folder”, /Volumes/music, and the network share. Please keep only one, or the same files will be imported more than once. Tell us which you want to keep, and whether you have edits or play history to preserve, and we will give you the safe order to remove the others.