I used video.js for the first time this week and it works well, but there is some confusion in the documentation as to how to get the Flash fallback to work.
It’s actually pretty simple. First off, do not use the CDN version. Use the self hosted version.
When you use the self hosted version, make sure your path to video-js.swf is accurate.
I know it sounds pretty simple but the way video.js documents things it makes it confusing to figure out. Plus the browser doesn’t tell you anything is wrong.
My issue was I only had an MP4 file and I wanted the Flash fallback for Firefox. Everything worked great in Safari and Chrome, but in Firefox I just got a black box. It looked like the video player loaded, there were no errors, but I couldn’t play anything.
Same goes for IE8. Black box, no errors, no video playing.
There are actually quite a few help topics on this, but all of them are unable to find the right solution. Everyone think’s it is a problem with video.js when in reality, it’s more of a documentation issue.
Once I got video.js running locally, my MP4 file played great in Firefox and IE8 via Flash.