I loooooooove the spell checker (and there's another red line!). I used to open word or google words if I had a brain-toot and forgot how to spell something (which means I never really knew).

Also, I upgraded with no problems regarding my bookmarks. I updated my theme, too which is rather snazzy.

https://addons.mozilla.org/firefox/72/

I hope everything came back and is working for you now!