Firefox advised a refresh because it was running slowly. I clicked refresh and now on relaunch (have quit and restarted several times) I cannot access any websites at all because on EVERY site I try to access I receive a message: 'Warning: Potential Security Risk' in a yellow framed page. Underneath the heading it says (for each site): 'Firefox detected a potential security threat and did not continue to support.mozilla.org. If you visit this site, attackers could try to steal information like your passwords, emails, or credit card details.' As you can see, this is even for Mozilla itself. I have no extensions. In addition, the menu section on Firefox (the only thing I can actually open) is showing up with all images blocked. Im having trouble uploading a screenshot for some reason so can't send that. I am currently on Chrome while unable to access anything on Firefox. Many thanks in advance. This has really put my whole day / work at a standstill!