I'm using Brave to write this, and there's no problem with internet access, obviously. 

OK, apparently Firefox updated today- Feb 2, 2021 and it said to restart Firefox for the changes to take effect. I did that and Firefox loads, but it does nothing. When I hit "Home" it tries to work but it's apparently not accessing the internet. I can't access options either. I didn't uninstall because I don't want to lose any current settings, bookmarks, history, etc. I use Windows 10 on my laptop. I did and automatic restart-- same result. I did a total shut down and restart-- same. I checked with McAfee firewall and Firefox has access. No note comes up regarding any issue when I load Firefox. I'm using Brave to write this, and there's no problem with internet access, obviously. So, which files or folders do I need to back-up so I can reinstall with bookmarks and history intact?