Thanks for the reply.
After setting up a new boot volume and migrating all my apps etc into it to make it the primary use volume, I also wanted to change the location of the folder that MC would use for album art.
The old location for this album art is still in place (on the desktop on the new boot volume).
So I consolidated and then duplicated this folder to the same HD volume as all of my music is stored on (a separate drive).
When I open this new folder (which is on the root level of my music drive), what I see is all the album art is grayed out and not selectable.
I can hit the 'open' button but MC responds with "There was a problem moving the cover art folder", and the newly selected folder location is ignored.
Also I can choose just the album art folder itself (without opening it) and then hit 'OK' but MC comes back with the same "There was a problem moving the cover art folder" with the only option of hitting the 'OK' button.
IOW I can't select this new location for the album art.
There is another anomaly which seems to be related but I can only guess.
The existing chosen album art folder (on the desktop) currently contains only 1 file (it should have 271 files).
I can repopulate this folder with the contents of all of my saved album art but after doing so and then attempting to change the location for the album art to its new location, all the files are deleted except for one.
IOW in making the attempt to change the location of the album art, the existing selected album art location has all of its contents deleted save for 1 file.
Thanks for looking into this JJ