Yet another reason to not use Chrome

[robkelk]

The original problem seems like an honest mistake, but the fix method seems surprising.  They built a system that allows them to insert arbitrary security certificates into the browser, and turned it on by default.  It feels like the kind of thing that could be leveraged by a nation state.

And that's the clue that I needed.

Instead of opening the browser up to surveillance, go into about:config and set xpinstall.signatures.required to false. I did this and uBlock Origin and Privacy Badger immediately re-appeared on my toolbar. Mind you, I also have Options|Security set to warn me if sites try to install add-ons.