Unrelated to cert problem: Yes, clicking on the link installs the plugin, but it is suprising to see that firefox claims that it is the news.ycombinator.com, not storage.googleapis.com, that wants to install plugin. Could it be a security issue since if an attacker somehow manages the post/inject a link for a malicious plugin in a credible site, firefox will claim that plugin is from that site?

oh wow! that's really bad

I just installed some random googleapis link. This is so stupid, and very disappointing from Mozilla.

This should be sticky comment somewhere on the top of the comments. It bought all the addons back for me.

It does, but it didn't fix anything for me. All my extensions are still gone. :(

You might have to reinstall them unfortunately, on the system I figured that out on Firefox had decided to uninstall them (I think because I had to update the browser from the ancient version the user was using first).

Just tried on Android. Hooray!

Clicking the URL was the only way I was able to get the hotfix on Firefox mobile for Android