Comment 3 for bug 1847890

Sorry but I didn't realize that I was limited to one attachment per comment. This comment has the first epub with the dc:identifer line intact.

The first attached epub has two fonts that are using Adobe obfuscation. If calibre updates the metadata, the <dc:identifier opf:scheme="UUID">urn:uuid:ef424b40-3f28-4fc6-ba08-2930290145bc</dc:identifier> line is removed from content.opf and the fonts are unusable.

The second attached epub with polished in it's name is the result of running Polish with update metadata ticked which removes the dc:identifier line.