Mozilla made the choice to permanently disable unsigned addons in the Release and Beta versions of Firefox. Now something has gone wrong with the signing certificate or server and all addons are seen as unsigned. Whenever the browser calls home to check for addon signatures, the check fails, so all addons are automatically disabled. Apparently even Tor Browser and Tails still call home to Mozilla. Shows the risk of placing trust in a single point of failure. Don't know when they'll fix the issue for everyone using their shitware.
What the fuck was Mozilla thinking when they thought it was a good idea to tie every Firefox extension to what's pretty much a killswitch?