This has been happening for about a week if i go to use facebook, youtube, or google i get an insecure connection page appear, screen shots have been added. it says i cannot add an exception and only started since the mozzilla update on the 27/01/16. I ran a full security search and nothing turned up, i am with bullguard and when they intervine a different screen would appear. i tried to uninstall updates but with windows 10 things are more complicated to find.