Final Cut Pro version 10.6 and later exports a bundle version of XML with a .fcpxmld file extension. This bundle contains a .fcpxml file and other data. (For more information, see https://developer.apple.com/documentation/professional_video_applications/fcpxml_reference/fcpxml_bundle_reference)
Our apps have been supporting .fcpxmld bundle files since Final Cut Pro 10.6 was released. However, some users have exported .fcpxmld files that can’t be used — our apps won’t read them, and they even fail import back into Final Cut Pro.
In Finder’s List view, a bad bundle will show as a Final Cut Pro Document. A good bundle will show as a Final Cut Pro XML Bundle.
One possible work-around is to re-export the XML from Final Cut Pro again, but choose an earlier version number of XML.