I've started intermittently getting this same ISE when moving from release info tab to tracklist tab while adding a release over the past few days. Hitting back, then again attempting to move to the tracklist tab, I then do get to that tab, though in most cases the tab (and the edit note, at the end) now contains random tracklist and editnote data from old add release edits.

Internal Server Error
Oops, something went wrong!

Error:

Caught exception in MusicBrainz::Server::Controller::ReleaseEditor::Add->add "Attribute (params) does not pass the type constraint because: Validation failed for 'HashRef' with value undef at /usr/local/share/perl/5.10.1/HTML/FormHandler.pm line 350
HTML::FormHandler::setup_form('MusicBrainz::Server::Form::ReleaseEditor::Duplicates=HASH(0xb...', 'params', undef) called at /usr/local/share/perl/5.10.1/HTML/FormHandler.pm line 247
HTML::FormHandler::process('MusicBrainz::Server::Form::ReleaseEditor::Duplicates=HASH(0xb...', 'params', undef) called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Form.pm line 105
MusicBrainz::Server::Form::unserialize('MusicBrainz::Server::Form::ReleaseEditor::Duplicates=HASH(0xb...', 'HASH(0xb868348)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard.pm line 534
MusicBrainz::Server::Wizard::_load_form('MusicBrainz::Server::Wizard::ReleaseEditor::Add=HASH(0xb2482c0)', 1, 'serialized', 'HASH(0xb868348)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard.pm line 239
MusicBrainz::Server::Wizard::_load_page('MusicBrainz::Server::Wizard::ReleaseEditor::Add=HASH(0xb2482c0)', 1) called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard.pm line 173
MusicBrainz::Server::Wizard::navigate_to_page('MusicBrainz::Server::Wizard::ReleaseEditor::Add=HASH(0xb2482c0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard.pm line 401
MusicBrainz::Server::Wizard::_route('MusicBrainz::Server::Wizard::ReleaseEditor::Add=HASH(0xb2482c0)', 'MusicBrainz::Server::Form::ReleaseEditor::Information=HASH(0x...') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard.pm line 133
MusicBrainz::Server::Wizard::process('MusicBrainz::Server::Wizard::ReleaseEditor::Add=HASH(0xb2482c0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Wizard/ReleaseEditor.pm line 92
MusicBrainz::Server::Wizard::ReleaseEditor::run('MusicBrainz::Server::Wizard::ReleaseEditor::Add=HASH(0xb2482c0)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server/Controller/ReleaseEditor/Add.pm line 23
MusicBrainz::Server::Controller::ReleaseEditor::Add::add('MusicBrainz::Server::Controller::ReleaseEditor::Add=HASH(0x96...', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 65
Catalyst::Action::execute('Catalyst::Action=HASH(0x9993e70)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add=HASH(0x96...', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
eval

{...} called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
Catalyst::execute('MusicBrainz::Server=HASH(0xa599b68)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add', 'Catalyst::Action=HASH(0x9993e70)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/StackTrace.pm line 94
Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xa599b68)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add', 'Catalyst::Action=HASH(0x9993e70)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 60
Catalyst::Action::dispatch('Catalyst::Action=HASH(0x9993e70)', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Controller.pm line 110
Catalyst::Controller::_ACTION('MusicBrainz::Server::Controller::ReleaseEditor::Add=HASH(0x96...', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 65
Catalyst::Action::execute('Catalyst::Action=HASH(0x986f850)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add=HASH(0x96...', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
eval {...}

called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
Catalyst::execute('MusicBrainz::Server=HASH(0xa599b68)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add', 'Catalyst::Action=HASH(0x986f850)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/StackTrace.pm line 94
Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xa599b68)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add', 'Catalyst::Action=HASH(0x986f850)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 60
Catalyst::Action::dispatch('Catalyst::Action=HASH(0x986f850)', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 257
Catalyst::Dispatcher::_do_forward('Catalyst::Dispatcher=HASH(0x2143608)', 'forward', 'MusicBrainz::Server=HASH(0xa599b68)', '_ACTION') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 237
Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x2143608)', 'MusicBrainz::Server=HASH(0xa599b68)', '_ACTION') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 377
Catalyst::forward('MusicBrainz::Server=HASH(0xa599b68)', '_ACTION') called at /usr/local/share/perl/5.10.1/Catalyst/Controller.pm line 84
Catalyst::Controller::_DISPATCH('MusicBrainz::Server::Controller::ReleaseEditor::Add=HASH(0x96...', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 65
Catalyst::Action::execute('Catalyst::Action=HASH(0x9993b58)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add=HASH(0x96...', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
eval

{...} called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1665
Catalyst::execute('MusicBrainz::Server=HASH(0xa599b68)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add', 'Catalyst::Action=HASH(0x9993b58)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/StackTrace.pm line 94
Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xa599b68)', 'MusicBrainz::Server::Controller::ReleaseEditor::Add', 'Catalyst::Action=HASH(0x9993b58)') called at /usr/local/share/perl/5.10.1/Catalyst/Action.pm line 60
Catalyst::Action::dispatch('Catalyst::Action=HASH(0x9993b58)', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 257
Catalyst::Dispatcher::_do_forward('Catalyst::Dispatcher=HASH(0x2143608)', 'forward', 'MusicBrainz::Server=HASH(0xa599b68)', '/release_editor/_DISPATCH') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 237
Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x2143608)', 'MusicBrainz::Server=HASH(0xa599b68)', '/release_editor/_DISPATCH') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 377
Catalyst::forward('MusicBrainz::Server=HASH(0xa599b68)', '/release_editor/_DISPATCH') called at /usr/local/share/perl/5.10.1/Catalyst/Dispatcher.pm line 105
Catalyst::Dispatcher::dispatch('Catalyst::Dispatcher=HASH(0x2143608)', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1611
Catalyst::dispatch('MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst/Plugin/Static/Simple.pm line 76
Class::MOP::Class:::around('CODE(0x27a0310)', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 159
Class::MOP::Method::Wrapped::_ANON_('MusicBrainz::Server=HASH(0xa599b68)') called at /home/musicbrainz/musicbrainz-server/script/../lib/MusicBrainz/Server.pm line 273
Class::MOP::Class:::around('CODE(0x9c080c8)', 'MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 159
Class::MOP::Method::Wrapped::_ANON_('MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/lib/perl/5.10.1/Class/MOP/Method/Wrapped.pm line 89
MusicBrainz::Server::dispatch('MusicBrainz::Server=HASH(0xa599b68)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1952
eval {...}

called at /usr/local/share/perl/5.10.1/Catalyst.pm line 1943
Catalyst::handle_request('MusicBrainz::Server', 'env', 'HASH(0x3505328)') called at /home/musicbrainz/musicbrainz-server/script/../lib/Catalyst/Plugin/AutoRestart.pm line 119
Catalyst::Plugin::AutoRestart::handle_request('MusicBrainz::Server', 'env', 'HASH(0x3505328)') called at /usr/local/share/perl/5.10.1/Catalyst/Engine/FastCGI.pm line 149
Catalyst::Engine::FastCGI::run('Catalyst::Engine::FastCGI=HASH(0x34d02f8)', 'MusicBrainz::Server', '127.0.0.1:55901', 'HASH(0x102dd48)') called at /usr/local/share/perl/5.10.1/Catalyst.pm line 2396
Catalyst::run('MusicBrainz::Server', '127.0.0.1:55901', 'HASH(0x102dd48)') called at ./script/musicbrainz_fastcgi.pl line 28"
Stack trace:
line 105 MusicBrainz::Server::Form
line 534 MusicBrainz::Server::Wizard
line 239 MusicBrainz::Server::Wizard
line 173 MusicBrainz::Server::Wizard
line 401 MusicBrainz::Server::Wizard
line 133 MusicBrainz::Server::Wizard
line 92 MusicBrainz::Server::Wizard::ReleaseEditor
line 23 MusicBrainz::Server::Controller::ReleaseEditor::Add
line 273 MusicBrainz::Server
Request data:

$VAR1 = {
'query_parameters' =>

{ 'artist' => '72c536dc-7137-4477-a521-567eeb840fa8' }

,
'body_parameters' => {
'artist_credit.names.0.name' => 'Bob Dylan',
'packaging_id' => '',
'date.month' => '',
'release_group_id' => '',
'labels.0.catalog_number' => '',
'wizard_page_id' => '0',
'release_group.name' => '',
'artist_credit.names.0.artist.id' => '17',
'labels.0.deleted' => '0',
'country_id' => '',
'labels.0.name' => '',
'date.year' => '',
'type_id' => '9',
'id' => '',
'script_id' => '28',
'status_id' => '3',
'step_tracklist' => 'Tracklist',
'date.day' => '',
'name' => "2009-04-08: Palais des Congr\x

{e8}

s de Paris, Paris, France (source 1)",
'gc-keepuppercase' => 'on',
'barcode' => '',
'artist_credit.names.0.join_phrase' => '',
'labels.0.label_id' => '',
'wizard_session_id' => '0.370949408956207',
'language_id' => '120',
'comment' => '',
'gc-mode' => 'English',
'artist_credit.names.0.artist.name' => 'Bob Dylan',
'annotation' => ''
}
};

URL: http://musicbrainz.org/release/add?artist=72c536dc-7137-4477-a521-567eeb840fa8