Go to about:config and set xpinstall.signatures.requiredto false
then go to about:debugging and check the box to enable add-on debugging.
Then click Load Temporary Add-On ... and browse to:
/home/USER_NAME/.mozilla/firefox/YOUR_PROFILE.default/extensions folder
Select ant load the .xpi files.

>>>>>> Don’t close Firefox until mozilla fix the issue.

  • [deleted]

  • Post #2
  • Edited

I only needed to toggle xpinstall.signatures.required in about:config none of that other stuff?