This problem only started around 10am today. I tried to check my hotmail account and got this message: he owner of outlook.live.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate. When I click on "Advanced," it says: outlook.live.com uses an invalid security certificate. I got in touch with outlook support and informed them that they have an insecure certificate. They claim that firefox is not working properly. So, now i have two companies pointing fingers at each others. I'm having no other problems with my browser-- all other websites are working fine, which leads me to believe that it is indeed a problem with outlook. I can't get them to do anything about it. Please help!