boxcarpress on "[Plugin: Peter's Collaboration E-mails] Custom taxonomies not loading in settings"

Finally was able to fix this. Don't ask me why, but my problem is solved by a slight change to line 1444 of peters_collaborations_emails.php. I use get_object_taxonomies:
$taxonomies = get_object_taxonomies( $post_type, 'objects' );
...instead of using get_taxonomies(). The same code applies to line 1528:
$post_type_taxonomies = get_object_taxonomies( $post_type, 'names' );
This bug was frustrating because the code worked on our development server but not on our production server. We replicate the DB and have the same codebase, so I really can't tell you why this would be the case. One (slight) difference is the PHP version, 5.4.9 in development and 5.4.6 in production. But anyway, I hope this helps.