firefox uses html5 now and if a site uses flash it will ask you to download it. That isn't something from firefox.

''sirthanksalot52 [[#question-1252583|said]]'' <blockquote> Must I download adobe flash into Firefox or is there a way to use what is already in my Edge with Firefox? If I download it from the Firefox window wont that create issues to have it downloaded twice?</blockquote> You need to install the NPAPI version of Flash Player to have Flash running in Firefox. It is not actually installed in Firefox like Extensions are but installed on system. You can type '''about:plugins''' in Location (address) bar to see where it is located if you install Flash. https://get.adobe.com/flashplayer/otherversions/ Adobe Flash is available by default in Microsoft Edge. There is no need to install additional software to make it work. Chromium/Chrome/Opera uses a PPAPI version of Flash, Internet Explorer aka IE uses a ActiveX version and web browsers like Firefox and SeaMonkey uses a '''NPAPI''' version of Flash. Many websites now days have been using a HTML5 player to be more cross platform compared to using the Flash Player Plugin. Youtube has been using HTML5 players by default for a few plus years now. https://www.youtube.com/html5 September 10 2013 was the last time Adobe updated Flash for Android and there is no Flash for iOS so HTML5 is handy for video, audio, and even games on more devices.