Just tried mine LiK - seems that the geeks may have fixed it at last - been broken here all morning - not sure that every extension is quite right yet - but the crucial ones are OK at the moment ..
I'm on a Macbook with the very latest version of Firefox, so can't provide conclusive evidence that Windows Firefox is OK for all versions of Windows and FF
easy fix sync your firefox first, then download firefox x32 or x64 version, uninstall firefox, reboot, install firefox sign back in to sync within firefox, it putss all your saved favorites back etc, then go to downloads and reinstall ublock or whatever blocker you use..done
worked for me.
Following someones's ( sorry, can't remember who's) advice, I have just downloaded Adguard and it is working a treat. I just wish I knew how to stop those annoying videos popping up in the Dailymail.
anotheoldgit, as i said, download firefox https://www.mozilla.org/en-GB/firefox/new/ to your download draw, then uninstall firefox, reboot
install firefox then go to tools addons search ublock origin, click install, ublock is my preferred blocker, you want to sync firefox by clicking on the three lines on the top right bar, sign up email etc, all your saved urls can be restored after you uninstall firefox by signing back in.