We are getting the error with Firefox and Chrome on some machines an not others, so it doesn't seem that it would be that we are trying to load a file in a nonsupported format in JW Player (which the troubleshooter suggests)
An MOV might be OK, as long as it's encoded as H.264, and as long as the server puts the correct MIME type on it. Converting to MP4 is the safer route, and the server might then automatically provide the correct MIME type.
Every file that a server provides comes with an HTTP header that tells the browser what kind of file it is. If you convert to MP4, but your server is STILL not providing the “video/mp4” MIME type, your server administrator needs to fix this. If you can edit your own .htaccess file on the server, you can add this line:
AddType video/mp4 .mp4
But it really would be best if the server administrator corrected the error in the server configuration.
Thanks - I've converted to a .mp4, updated the htm - but it appears even worse (at the moment) - seems the MIME type the server is providing is text/ html. (As long as I didn't do anything else to screw it up).
It's surprising how many web hosts get the MIME type wrong on MP4 files. When they were always being displayed with Flash it didn't matter, but these days, it's a real problem. Even major cloud services like Amazon AWS manage to screw this up!
In short, you're not alone. Small comfort....
Handbrake is excellent - just make sure you've checked "Web optimized." That puts the moov atom at the beginning of the file, so it can be streamed (i.e., the visitor doesn't have to wait for the whole video to download before it starts playing).