Ah, so that’s what’s going on. All my Firefox add-ons are disabled because the intermediate signing cert expired, so it can’t verify ANY of them.
Not too thrilled at having my privacy add-ons remotely disabled, mind you. I appreciate checking signatures on installation/upgrade, but that shouldn’t introduce a remote dependency on a single point of failure to keep using things that have *already* been verified.
https://www.engadget.com/2019/05/03/firefox-extension-add-on-cert/