Gallery App: Blank Page When Creating Album

I'm getting a blank page when trying to create a new album in the Gallery App.

I can fill in the Title, Description and Order fields but when saving I get a blank page. Nothing is submitted to the database. Noticed a recent thread that had a similar issue: https://forum.grabaperch.com/forum/03-11-2015-blank-page-when-trying-to-add-pages

Error log:

[Wed Mar 11 13:33:50.037567 2015] [:error] [pid 7400] [client 127.0.0.1:52350] PHP Fatal error:  Call to a member function return_instance() on a non-object in /Users/danlee/Sites/Work/bell/login/core/lib/api/PerchAPI_Form.class.php on line 407, referer: https://bell.dev/login/addons/apps/perch_gallery/edit/