This morning I added a cover art picture to the following release
The cover art shows correctly on the web page for the release, but Picard will not load the picture when I try to tag the album. The error log includes the following report:
E: 21:12:33 Network request error for https://ia801509.us.archive.org:443/18/items/mbid-0f7424ce-24a1-479d-a1b6-5f7c37febf61/index.json: Error downloading https://ia801509.us.archive.org:443/18/items/mbid-0f7424ce-24a1-479d-a1b6-5f7c37febf61/index.json - server replied: Not Found (QT code 203, HTTP code 404)
E: 21:12:33 CAA JSON error: Error downloading https://ia801509.us.archive.org:443/18/items/mbid-0f7424ce-24a1-479d-a1b6-5f7c37febf61/index.json - server replied: Not Found
Based on the discussion in a seeming related post (see below), I waited now about 10 hours for the problem to resolve on its own, but so far this has not happened.