Looking at the details of the edit, you have "label":{}, which to me looks like it should never happen. I tried to reproduce this by editing the same release locally, but just ended up with one edit release label, and one add release label. Later, we will have the same data loaded on to test.musicbrainz.org - if you could try their to reproduce the problem and give precise steps, I should be able to hunt this down

Another example http://ngs.musicbrainz.org/edit/14460694

Happened to me as well: http://ngs.musicbrainz.org/edit/14459779

I've added a work around that now lets us display these edits correctly

Broken again, sigh.

Could this be what causes http://musicbrainz.org/edit/14499788 to show "An error occured while loading this edit" ?

More edits of mine where this seems to have happened:

http://musicbrainz.org/edit/14503645
http://musicbrainz.org/edit/14503157

Another from yesterday - http://musicbrainz.org/edit/14603253