Mozilla sets termination date for Firefox's legacy add-ons

Mozilla this week laid out the roadmap for ending Firefox support for all old-school add-ons, telling users that the end of those legacy extensions would come in just two weeks.

"Mozilla will stop supporting Firefox Extended Support Release (ESR) 52, the final release that is compatible with legacy add-ons, on September 5, 2018," wrote Caitlin Neiman, add-on developer community manager, in an August 21 post to a company blog.
FIREFOX ESR is the version designed for enterprises and other users who want a more static browser; Mozilla upgrades ESR about once a year, as opposed to the every-six-week standard feature update tempo. Firefox ESR 52, destined to fall off the support list in two weeks, was first issued in March 2017. Its replacement, Firefox ESR 60, debuted in May of this year. Since that latter date, Mozilla has been regularly updating both ESR versions to give customers time to migrate from version 52 to version 60.