Use Flash? QuickTime? Java? If you use these to make your Firefox experience more awesome, check your plugins! They may need to be updated.
Firefox will begin retiring Adobe Flash on August 2 with the release of Firefox 48. In probably with Firefox 53, Flash plug-ins will require.
Adobe Flash Player is the standard for delivering high-impact, rich Web content. Designs, animation, and Macintosh OS X, Firefox, Safari - NPAPI, Adobe Flash Player · About flash · Product Licenses and Terms of · Statistics. Install Adobe flash player on ubuntu for Firefox