When a track has an artist with a trailing join phrase (for example "Baz Luhrmann" + " presents") though no adjoining artist, the phrase is non-existent in the editor and thus not editable. This applies to both the basic and advanced editors.

Please see [1] for an example.

[1] http://test.musicbrainz.org/release/d3ef6e12-0174-42a1-aa8b-3a9fc55af09a/

Additionally, if the release artist is set to "Baz Luhrmann" + " presents" then the track artists become uneditable (see [2]). This even applies if the release artist has only been changed to the aforementioned while in the editor.

[2] http://test.musicbrainz.org/release/1ead5d4c-d102-4a5e-a173-5d2393fd1b04