What to do about Firefox 71.0 update breaking many extensions and it's own UI?

The recent update to version 71 of Firefox broke many extensions and parts of firefox' own UI. E.g. after the update on 18.04 Ubuntu, uBlock Origin, URLs List and Vimium stopped working on two of my computers. Also my whole bookmark toolbar appears empty in all windows but the first one opened and most of the toolbar icons are invisible.

Many co-workers report the same issues and I've read complaints about whole profiles being delete or Firefox not starting after the update.

Is there already a patch for that somewhere (even if experimental)? If not is there a save way to downgrade?

1 Answer

Okay so my problem was fixed by these steps:

• Run firefox --profileManager and create a new profile
• Copy all .sqlite files from .mozilla/firefox/<oldprofile> to the new profile's directory (I did not traverse subdirs in my search for sqlite files)
• Copy key4.db and logins.json (they only work if you have both)
• Copy handlers.json
• Start firefox with the new profile (and make it default if you want)
• Install all your old addons. You can see what you had installed via this python one-liner:

python3 -c 'import json; a = json.load(open(".mozilla/firefox/<oldprofile>/addons.json")); print("\n".join(x["name"] for x in a["addons"]))' 

As far as I can tell, I lost the settings for my old installed addons, but they were not important to me. Everything else seems as before. I have deliberately copied only files that were absolutely necessary as to not copy the malfunction along.