mozilla/butter — pull request #1557 by cadecairos (2013-03-07 16:19:09+00:00)
Title: [#3311] Check that _popcornOptions.fallback exists

Lighthouse: https://webmademovies.lighthouseapp.com/projects/65733-popcorn-maker/tickets/3311-clip-editor-unusable-with-older-project-media#ticket-3311-4