Ok, so from this thread
I learned how to fix tracks from streaming services that have become unavailable.
Now that I have completed the exercise of replacing all unavailable tracks in my library, I found that the tracks that library maintenance proposes to remove here…
…are unrelated to these unavailable tracks on streaming services. Because the number did not drop after I replaced them all (and yes, I restarted the server to be sure). This is NOT what I expected.
Which leads me to think that performing this cleanup, which I have never dared to do, may be more harmless than I thought: perhaps these are simply entries in Roon’s database which are not actually listed in your library anymore. Any thoughts?