Java Downloads for All Operating Systems

Make sure your Java (Not JavaScript) is up to date Verify Java and Find Out-of-Date Versions {web link}

Version 8 Update 101 Release date July 2016 http://java.com/en/download/manual.jsp

All versions of the Java Deployment Toolkit are soft-blocked since 2013. Oracle hasn't fixed the vulnerabilities with that plugin; typically only used by Java Developers and with some vertical market software, not by the "average user".

It can be enabled as needed. https://support.mozilla.org/en-US/kb/how-allow-java-trusted-sites

It would be a highly unusual site that uses the Java plugin to play a video. Is it possible that there's a problem with the Flash plugin?

When you are on a site where plugin content isn't working, could you click the plugin notification icon to see what's going on? The icon usually appears at the left end of the address bar, and looks like a small dark gray Lego block. If the page wants to use a plugin with a serious security problem, the icon may appear in red. Does that provide any additional information?

Alternately, if sites are telling you that JavaScript is not enabled, that's something different. JavaScript is a scripting language that Firefox interprets internally, not using the Java plugin. Usually JavaScript is enabled on all sites, but some extensions may disable it. Could you test in Firefox's Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?