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Firefox - all addons disabled (66.0.3)


firefox-logoAs you have probably noticed, all your addons have been disabled with the latest firefox update (66.0.3), with this error message: extensions "could not be verified for use in Firefox and has been disabled". This is because Mozilla foundation is cracking down on extensions with obfuscated code. (Link for more reading)

At the time of this writing, there's only a temporary solution, which allow to re-enable the addons per-session. Once a more permanent solution is found, it will be posted here:

To re-enable your extensions, open to about:debugging in the browser address field

Click the 'Load Temporary Add-on' button

Navigate to the .xpi file in your profile directory select it and click Open.

To find your profile directory and extensions:


C:\Users\{your username}\AppData\Roaming\Mozilla\Firefox\Profiles\{profile id}.default\extensions


~/.mozilla/firefox/{profile id}.default/extensions/


~/Library/Application Support/Firefox/Profiles/{profile id}.default/extensions

If you have removed the addons, you may still be able to re-download it from

  1. Right click on the 'Add to Firefox' button
  2. Choose 'Save Link As' from the menu
  3. Save the .xpi file
  4. Navigate to about:debugging
  5. Click the 'Load Temporary Add-on' button
  6. Navigate to the .xpi file you downloaded and open it

Because this is a temporary fix, you will have to repeat this every time the firefox is closed and re-opened.

Alternative solution is to switch to Firefox Development edition (or Nightly).

Once migrated, go to: about:config and set xpinstall.signatures.required to disabled. This will re-enable the addons.

Firefox bug reported:


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