Firefox is about to lose a ton of its users over this. I saw this on a family member's computer just now, couldn't get ublock origin installed or any extension for that matter. Had to install Chrome for them.

This has to be some type of a bug, every extension gets disabled with zero notice and cannot be re-downloaded.

I'm not seeing it myself yet, but haven't restarted firefox in a few hours.

Has anyone tried disabling xpinstall.signatures.required in about:config? Saw someone mention it elsewhere, but didn't try it in time.