Earlier quoted context omitted.
In this day and age you're living on borrowed time using an old version of a web browser. This state of affairs has its good and bad, but your modern-day browser vendors don't typically maintain branches of old versions to make security and bug fixes (especially when they change things for security reasons, as with this case of old-style addons being removed). If you're going to insist on using an old unsupported ver…
Well I've just been educated on a new mechanism by which things can be remotely broken.
I wanted to point out this wasn't remotely broken, however. Even if you had no internet connection, your addons would have stopped working when the certificate expired.
(Disclosure: I work for Mozilla)