Removing Support for Unpacked Extensions

With the release of Firefox 62 (currently scheduled for August 21, 2018) Mozilla will discontinue support for unpacked sideloaded extensions. You will no longer be able to load an extension via the Windows registry by creating an entry with an extension’s directory (i.e. unpacked) after Firefox 61. Starting with Firefox 62, extensions sideloaded via the Windows registry must be complete XPI files (i.e. packed).


Removing a Legacy Heritage

Support for unpacked extensions was originally a feature used by legacy extensions. With the release of Firefox Quantum (57) and the transition to the WebExtensions architecture for add-ons, support for unpacked extensions is no longer required. Maintaining support for both unpacked and packed extensions places a significant technical burden on the engineering and testing organizations, and removal of the legacy unpacked extension code helps Mozilla preserve the long-term stability of Firefox.

Convert Unpacked to Packed

If you are the developer of an extension that has been installed via the Windows registry as an unpacked directory, your extension will continue to work through Firefox 61. Starting with Firefox 62, however, your extension will be no longer be loaded by Firefox. To avoid this situation and ensure users do not lose functionality, please pack your extension and update the Windows registry entry to use the packed XPI file (see MDN for detailed instructions).

Development Still Supports Unpacked Extensions

Note: this does not impact the use of unpacked extensions for development. Temporarily loading and debugging an extension either via the about:debugging page or via the web-ext tool will continue to be supported; both methods will still be able to load extensions contained within a filesystem directory. Developers will not be required to sign or pack their extensions into an XPI file for development purposes.

3 comments on “Removing Support for Unpacked Extensions”

  1. ff wrote on

    a very poor, even hostile decision. you wreck thousands of well working software installations by millions of users.

    much worse than when all python2 programs were rendered obsolete without rhyme or reason by Python v3.0

    FFox ESR will be the new world – wide standard.

    1. r park wrote on

      @ FF ~ FFox ESR will be the new world – wide standard?
      We can only hope not! They have already done enough to destroy their image! An give worldwide headaches to all their users! All for the love of money! Sad! Truely, Sad!

  2. r park wrote on

    Firefox keeps bragging about newer versions of their browser, but they refuse to fix the problems people complain about all the time! You keep jacking with settings, and in doing so You mess up something else. Like video streaming! Back when You sold us out to all of google tracking, it made it worse. An if that isn’t bad enough, You mess with settings, rename those settings so we can’t, go back and change them because we don’t know what You call them now. There is nothing I love more then watching a video, and to have it buffer every time You turn around. An no it’s not my internet speed, it is fast! Or watching movies on Vudu, and have to listen to snap crackle pop in the audio. An no my audio system as is video card is just fine. I love how when people write in and complain about stuff, You always throw out it has something to do with there equipment, or IP provider, when anyone with digital age smarts knows where the real problem lays. Firefox, and the garbage called Google. If anyone had any sense, they would boycott Both Firefox, and Google! I always said Internet Explore stunk! But when it comes to playing videos, they beat Firefox/Google all to hell! I guess it’s time to say goodbye to Firefox, and if anyone had any sense, they would do the same. But they won’t, they will just keep on complaining, and keep the headaches. But if they did, I bet my bottom teeth, it wouldn’t take long for You to fix the problems, would it?