Please update your plugins to the latest version. Check to make sure you are up to date:

• https://www.mozilla.org/en-US/plugincheck/

If you see any issues also see:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

This did not solve the problem. The video at this site worked fine with FF41 and an older version of Flash so I do not know what caused the problem or perhaps something with the web site. In searching through the Mozilla Support Resolved questions I found an identical issue as mine that was solved with an additional CSS text file. I lost the location of that solution and can not find it again. Can someone help me fine that solution? Thanks.

You can check for problems with current Shockwave Flash plugin versions and try this:

• make sure you have the latest Flash version:
  http://www.adobe.com/special/products/flashplayer/fp_distribution3.html
• check for updates for your graphics drive drivers
  https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration
• disable protected mode in the Flash plugin (Windows Vista and later)
  https://support.mozilla.org/kb/adobe-flash-protected-mode-firefox
• disable hardware acceleration in the Flash plugin
  https://helpx.adobe.com/flash-player/kb/video-playback-issues.html
• disable hardware acceleration in Firefox
  https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

See also:

• http://kb.mozillazine.org/Flash#Troubleshooting

Problem solved. Thank you. I had to disable hardware acceleration in the Flash player. That fixed it.