Since I installed Fedora 30 I have been unable to load any extensions. I keep getting a message to check my connection, but my connection to the web is just fine.
It’s not just you. It’s caused by the expiry of addon intermediate certificate. See https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/ for latest updates and fixes
What your’re doing is participating in a STUDY in 15 minutes you get the fixes…
to see your studies type in your browser: --> about:studies
Mozilla screwed up. You need to either install version 66.0.4 manually or wait for it to be included in dnfdragora updates. Should be soon.