This is partly a comment and a question.
- For albums, there is typically an image "Folder.jpg" that is the cover art for the album.
- In "Playlist" folders, there is no cover art file. And each file comes from a different album. How do media players find the cover art for these different tracks and albums?
- After I moved the folders, I no longer get the "CoverartPath is empty" message. But also, I get the standard XXHE "X" cover art page when there is no cover art image.
- Playing the same files with Windows media player, the player seems to extract a cover art image even without any image file anywhere.
This is easy answer: XXHE does not read so called 'file header' or at least not beyond sample rate and bit depth while most other players do read local file header or search song / album cover on internet. Several websites collect such infos: Discogs, MusicBrainz, freedb to name the few.