Youtube, Vimeo, and DailyMotion videos will not work over https:// due to the unnecessary hardcoding of the $src parameter in php/general.php . When viewing pages with your code over https, the videos simply fail to load on most modern browsers due to mixed-content.
In each case, simply removing the unnecessarily hard-coded protocol works:
$src = '//player.vimeo.com/video/'...
$src = '//www.youtube.com/embed/'
$dm['src'] = '//www.dailymotion.com/embed/video/
We've been making this edit internally and supporting SSL for WordPress is an absolute must. I hope you'll consider adding this to a future update to save us and others the upgrade maintenance.