Added this release: http://musicbrainz.org/release/ab08beb9-9550-4d6b-8790-038309dc1aeb. On the tracklist page I wanted to change the artist field so that it did not include the performers. I clicked "edit" on the first track, deleted all the artists and deleted the join phrase. I then clicked "next". In the past this would change all the matching tracks (in this case that should be all of the tracks) but in the past few months this seems to be broken. I have to copy/paste credits for each track.
I am using Firefox 45.4.0 on linux (debian).