Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work?

Revision Information
  • Revision id: 142709
  • Created:
  • Creator: Artist
  • Comment: for not fx52: support has ended (instead will end) in March 2017
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: AliceWyman
  • Is approved? Yes
  • Is current revision? Yes
  • Ready for localization: No
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Revision Content

Support for NPAPI plugins in Firefox – except for Adobe Flash – has ended in March 2017, when Firefox version 52 was released.Beginning in Firefox version 52, support for NPAPI plugins in Firefox has ended, except for Adobe Flash. Some of the plugins that will no longer load include Java, Microsoft Silverlight and Adobe Acrobat. See this compatibility document for details.

Over the past few years, Firefox has implemented various Web APIs so that websites can do the same things they’ve always done without plugins, so you will most likely not notice any change to your browsing experience.

Why did Firefox do this?

The internet is full of websites that go beyond static pages, such as video, sound and games. NPAPI plugins, especially Flash, have helped enable these interactive pages. But they also make your browsing slower, less secure and more likely to crash.

Over the past few years, Firefox has worked hard to build replacements for these plugins. Together, they are called Web APIs. They are designed to replace the function of these plugins without undermining your internet security, stability and performance.

Before, these Web APIs weren’t quite ready, so Firefox started the transition by making plugins load manually (click to activate).

Today, they’re ready. Many sites have adopted them, and almost all your favourite pages can be enjoyed without using old and insecure plugins. Firefox joins other modern browsers like Google Chrome and Microsoft Edge to remove support for these NPAPI plugins.

I’m having problems

In case you’re not yet ready for this transition to happen, the ESR (Extended Support Release) of Firefox 52 will continue to support these plugins until early 2018. Click here to download Firefox ESR.

Important: The Windows 64-bit version of Firefox 52 ESR only supports the Adobe Flash and Microsoft Silverlight plugins. If you also need support for Java or other plugins, choose the Windows (32-bit) download.

By default, Firefox 52 ESR will use the same user profile data as other versions of Firefox. Installing Firefox 52 ESR after using Firefox version 55 or above can cause problems such as error messages, breakage in portions of Firefox and issues with some websites. You should either create a new profile to use with Firefox 52 ESR or else refresh Firefox after installing Firefox 52 ESR.