There exist multiple bugs in v2.38 when attempting to look up albums in Amazon/Discogs. I'll spell them out here:
1) HTTP requests are not being URL encoded. The text entered in the GUI is being put directly into the HTTP request, which fails because the server expects proper URL encoding. An example is this artist:
If you type that name into the Discogs Artist dialog box, mp3tag makes a request to the server:
184.108.40.206 HTTP GET /artist/S\351bastien+L\351ger HTTP/1.1
This is clearly wrong. If, instead, you type "S%C3%A9bastien+L%C3%A9ger" into the dialog box, it correctly locates the artist.
2) Amazon/Discogs responses are not being correctly handled as UTF-8. If you make a request to fetch an album which has non-ASCII UTF-8 encoded characters in it, the dialog shows you garbage in place of the real characters because they are not being translated from UTF-8 back into UTF-16 before being used in Windows and the mp3 tags.
An example album is:
If you type in the Discogs search "Isol%C3%A9e" to get around the first bug, and then select the "Rest (CD)" album, you will see garbage in the track listing where it should display "Démon"