I have been trying several times to create a 4CD release, with no luck (502 errors have been returned). This time, however, I get this message:

Error:

Caught exception in MusicBrainz::Server::Controller::ReleaseEditor::Add->add "Died at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard/ReleaseEditor.pm line 1226."

Stack trace:
line 1226 MusicBrainz::Server::Wizard::ReleaseEditor
line 1227 MusicBrainz::Server::Wizard::ReleaseEditor
line 1192 MusicBrainz::Server::Wizard::ReleaseEditor
line 778 MusicBrainz::Server::Wizard::ReleaseEditor
line 155 MusicBrainz::Server::Wizard::ReleaseEditor::Add
line 850 MusicBrainz::Server::Wizard::ReleaseEditor
line 779 MusicBrainz::Server::Wizard::ReleaseEditor
line 94 MusicBrainz::Server::Wizard::ReleaseEditor
line 23 MusicBrainz::Server::Controller::ReleaseEditor::Add
line 326 MusicBrainz::Server
line 326 MusicBrainz::Server
line 326 MusicBrainz::Server
line 275 MusicBrainz::Server

Request data:
$VAR1 = {
'query_parameters' => {},
'body_parameters' =>

{ 'save' => 'Enter edit', 'wizard_page_id' => '5', 'edit_note' => 'I recently bought these CDs. The listing and CD titles can be seen here: http://www.amazon.co.uk/Simply-Ballroom-Columbia-Orchestra/dp/B000OCZ92I', 'id' => '', 'wizard_session_id' => '0.82278891726278' }

};

URL: http://musicbrainz.org/release/add