Are you receiving the 'Blocked loading mixed active content' error when trying to play a video (YouTube or otherwise) through Lightbox? Well, it's a fairly simple one to diagnose, but without Firebug you might not even see the error and just receive a blank white screen of death (or greyed out embed code).

It occurs, because most likely you are trying to load the video through http:// whereas you are viewing the entire page through https://. Browsers don't like a mix of the two as it can be insecure.

Annoyingly, the Drupal lightbox plug-in has hard-coded the paths to it's modal video content. So even if you enter the url as, for example,, it will still try to display the insecure version of


Simple fix, head on into modules/lightbox2/js/lightbox_video.js and change those paths! Have a search in there for 'http://' and change the relevant (or all) paths to 'https://'.

Reupload the file, clear those caches, breath a sigh of relief and go and pour your next cup of coffee...