''locking a a duplicate of [/questions/1149496]'' I was just on Facebook before updating Firefox to 50.0.2 on Windows XP....now I can not sign into Facebook. I had to download the Chrome just to see if I could sign in on that browser...and yes, I was able to get on quickly. Here is an image that I am getting.....I have been trying all day (I would wait for about an hour and try again). Not only my account but also another account. I will contact Facebook and let them know also. But does anybody have any suggestions so I don't have to use Chrome ( I really don't like it cause I can't get the updates because I am using XP.