[FIX] Armageddon in Firefox: Most add-ons disabled!

Update: It appears Firefox 66.0.4 has resolved the issue. Chances are you have never experienced this problem.

On 4 May 2019, one of the Mozilla digital certificates used to sign Firefox add-ons expired. With this certificate no longer able to verify the authenticity of the add-ons, user across the faced the loss of access to their Firefox add-ons.

If you are blind and can't see this image, don't worry; you are not missing much.
All (or most) of your add-ons have ceased to function. Notice the new “Unsupported” tab.

This post teaches you how to recover from this failure in about 15 minutes and resume your daily routine work as if this has never happened.

  1. Install Firefox Developer Edition. This edition of Firefox is installed side-by-side and does not overwrite your current Firefox.
  2. Open Firefox Developer Edition.
  3. Open > Help > Troubleshooting Information.
  4. Locate “Profile Folder” and click on “Open Folder”. File Explorer will appear, showing your profile folder. (If you are in macOS or Linux, this step might be slightly different. Bring your intelligence to bear! You are going to need it.)
  5. Close Firefox Developer Edition and wait until it is completely closed. Use the Task Manager to verify its complete end.
  6. Navigate to the parent folder. You should be in a folder whose address reads: C:\Users\Your Username\AppData\Roaming\Mozilla\Firefox\Profiles.
  7. Create a backup of the entire profile folder. (I stress that this step is very important. Do not overlook it.)
  8. You should be able to locate both the Firefox Developer Edition profile folder as well as your old Firefox folder. Delete the contents of the Firefox Developer Edition profile and copy the contents of the ordinary Firefox profile to your Developer Edition profile.
  9. Disable your Internet connection, e.g. unplug your Ethernet cable, turn off your Wi-Fi receiver or disconnect your Mobile Broadband plan.
  10. Start Firefox Developer Edition. It must be looking exactly like your ordinary Firefox now, with bookmarks, settings, layout and everything else intact.
  11. Type about:config in the address bar and press the Enter key. Read the ensuing warning and confirm that you know what you are doing.
  12. Search for xpinstall.signatures.required.
  13. Set it to false. Double-clicking its entry should work
  14. Re-enable your Internet connection.

Now, all you have to do is to wait for Mozilla to fix this problem. Hopefully, you don’t have to wait long. You may then return to your ordinary Firefox.

Posted on 2019-05-04, in Computers and Internet, Windows Administration and tagged , , , , , , . Bookmark the permalink. Leave a comment.

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