I used the Tag Sources -> Cover Art -> Musicbrainz option on a selection of 13 files in the same directory, but Mp3Tag does not save the image to the selected files saying "saved tag in 0 files" in the status bar (screenshot attached). Text changes to tags are saved just fine. What's odd is, there is no error message either, so there's no idea as a user on what's happening under the hood.
I verified that the cover art I'm trying to set for the files in question is only 104KB, with the resolution being 512x512. This is a bug.
Also, if there's any issue, should Mp3Tag not display the reason for error, whether in a pop-up window, or in a more informative status bar message, instead of the "Saved tag in 0 of 0 files" message?
Thank you for the check of the Utils menu.
Now a screenshot of the web source results dialogue for the selected files would be nice (the one where you align the files with the titles).
Can you save the cover with other means in the files?
Do you get the cover in the file system if you select "Save image to disc"?
This was the issue. Thanks for pointing out. The cover art is saved to the FLAC files now. I have dark mode set, and did not notice the checkbox. However, a user going through the cover art menu to save cover art implies that this checkbox should be checked by default. Curious, why it is unchecked by default.
The Websource scripts share the same configuration regarding the checkboxes. You likely disabled this checkbox in another Websource script—one that is not limited solely to covers.