Are you sure you really need the Java plugin? Most sites do not use Java applets any more, and you do not need a plugin to execute JavaScript, that is handled directly by Firefox itself.

The regular releases of Firefox 52-57 only allows one plugin, which is Flash. The Extended Support Release (ESR) of Firefox 52 will still run Java, Google Talk, and other old plugins. More information on this change and ESR: Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work?

I know I need Java because I was unable to execute a .jsp just yesterday https://www.bhphotovideo.com/find/HelpCenter/helpcenter.jsp/mode/edu

Hi Madrikh, with JSP, the server processes the Java code and sends browsers pages with standard HTML, CSS and JavaScript. Which part of

https://www.bhphotovideo.com/find/HelpCenter/helpcenter.jsp/mode/edu

is not working correctly for you?

With either Privacy Badger or Firefox's built-in Tracking Protection feature (What happened to Tracking Protection?), content from other servers may be blocked, including servers the site requires to operate correctly. You might need to use the PB toolbar button or the Tracking Protection "shield" icon to make an exception for some pages.

Thanks. I'm not so concerened about a partiocular website as I am about the fact the the "java-app" plugin doesnot show up in the plugins list. The text of the help page at https://support.mozilla.org/en-US/kb/use-java-plugin-to-view-interactive-content says that this should show up. I've had a few oddities with recent Firefoxes (such as files from one particular that come in to Safari as .pdf but show up in firefox as .ASP (!). I don't know whether that is a java issue or somethig else, but if I should have a "Java Applet Plug-in" I'd like to know why not and what to do about it. If, contrary to the Mozilla page referenced above, Java apps will never run again in Firefox, I may need to find a replacement browser.

Madrikh said

Thanks. I'm not so concerened about a partiocular website as I am about the fact the the "java-app" plugin doesnot show up in the plugins list. The text of the help page at https://support.mozilla.org/en-US/kb/use-java-plugin-to-view-interactive-content says that this should show up. ... If, contrary to the Mozilla page referenced above, Java apps will never run again in Firefox, I may need to find a replacement browser.

As noted in the large box at the top of the article, the Java plugin does not run in Firefox 52+ (except Firefox 52 Extended Support Release).

If you can't do your job without Java, or you can't live without old Pogo games that require Java, then you'll need to visit those sites using a browser that still supports it. I think those two browsers are Safari on MacOS X and Internet Explorer 11 on Windows.

Other browsers like Chrome (since 45.0), Chromium and Opera has dropped support of NPAPI Plugins since Sept 2015 so there is even less of a reason for websites to still need the vulnerable Java Plugin from Oracle to be used.

The only NPAPI Plugin that is still allowed to run in Firefox since the 52.0 Release is the Flash Player Plugin from Adobe and will be until as late as end of 2020. https://blog.mozilla.org/futurereleases/2017/07/25/firefox-roadmap-flash-end-life/