See the Add-ons page of the Download Helper extension. *https://addons.mozilla.org/firefox/addon/video-downloadhelper/ <blockquote><pre> We are aware of downloading issues when using Firefox 36. We have been working for months on a 100% new version which works on Firefox 36+ (it does not work on Firefox 35 and below) and we just released a first test version. If you want to test this version and provide feedback on it, please follow this link.</pre></blockquote> *https://groups.google.com/forum/#!forum/video-downloadhelper-5