Firefox armagg-add-on: Lapsed security cert kills all browser extensions
Found on The Register on Monday, 06 May 2019
Every single web extension, theme, search engine plugin, and language pack had been nuked from netizens' Firefox installations, stripping any data and settings associated with them as they were removed.
For those using the Netflix add-on, there would be no video. For those using HTTPS Everywhere, there would be no enforced privacy. And the situation was similar for users of password management add-ons, content blocking add-ons, and the like.
It's not like monitoring expiration times of certificates is impossible. Any decent monitoring agent can do that.