Please consider turning on send info to Mozilla from within Firefox before posting. This information is useful to diagnose issues.

Please update to 57.0.2 https://support.mozilla.org/en-US/kb/update-firefox-latest-version

Long shot, Did you miss a Video Card Driver Update or anything in the install. (if info was sent would have seen errors in drivers if any.)

New version of Flash Released this date : Flash Player Version: 28.0.0.126 Current Version https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, . . . .) Note: Other software is offered in the download. <Windows Only>

https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues

https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows

https://support.mozilla.org/en-US/kb/html5-audio-and-video-firefox

Please let us know if this solved your issue or if need further assistance.

byerlythomas2 said

I just install Fedora Linux on my machine and updated everything including Firefox. I went to cybrary.it and tried watching a video and got this warning "Major bummer. This video can’t be played with your current setup." I understand that they video is hosted on vimeo.

One package Linux users may not install right away is FFmpeg so they can fully use the HTML5 player in browsers like Firefox and SeaMonkey. A place you can use to check what you support is at https://www.youtube.com/html5/ as all checks should be blue.

The Vimeo videos are HTML5 and not using Flash Player Plugin.