Adobe announced its roadmap to stop supporting Flash at the end of 2020. Starting next month, users will choose which websites are able to run the Flash plugin. Firefox users will still have the opportunity to enable Flash on specific sites that require it. Flash will be disabled by default for most users in 2019, and only users running the Firefox Extended Support Release (ESR) will be able to continue using Flash through the final end-of-life at 2020. Browser makers have prepared a guide to help website authors transition away from Flash technology.”]
Source: https://blog.mozilla.org/futurereleases/2017/07/25/firefox-roadmap-flash-end-life/