Firefox add-ons disabled en masse after Mozilla certificate issue

Firefox users report having add-ons disabled, being unable to re-activate or (re)-install extensions.

Firefox - Wikipedia

Planet Mozilla

Firefox 44 Brings Bug Fixes, Brotli, and Better Warning Page

All of my Firefox add-ons have been disabled suddenly, how can I

Upgrading to Firefox Quantum? Expect Some Add-ons to No Longer Work

Remove a Root Certificate in Firefox

Installing root certificate in Mozilla Firefox - WebMoney Wiki

Armagadd-on redux: Certificate expiration caused Firefox to

Why has Firefox just disabled all seven of my add ons?