The yahoo web page I am wanting to go to is below" 

The security certificate presented by this website was issued for a different website's address.

Thank you, I await your favorable reply.

I have never had this problem before with Firefox. and I recently updated firefox, and I now can't access Yahoo.com where my email is located ? I can access yahoo just fine on all other computers in my home but one, the one computer that, I recently updated firefox . I can't believe that yahoo.com is not safe! or that they have configured their web site incorrectly.....really?. i am speaking about Yahoo.com here! and I can easily access yahoo.com using another computer here in my home. Firefox is stating the following: The owner of mail.yahoo.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. I read the articles I found at Mozilla links. and still I have the problem. I have cleared the cache history. the yahoo web site has https: The yahoo web page I am wanting to go to is below" https://mail.yahoo.com/ internet explorer has the same problem! but does take me to Yahoo's news page, BUT, when I click to sign in to yahoo, so I can check my email, I am stopped, and explorer says this: There is a problem connecting securely to this website. The security certificate presented by this website was issued for a different website's address. Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server. You should close this webpage. I am stumped! is my computer infected with some thing that is trying to redirect my web surfing? or some type of infection; any type of infection? I am using COMODO anti virirs, and Malwarebytes. they report they are up to date and functioning properly and there are no infections reported from their scans. ....SO I'm very confused! and desperately need your help please. Please give me step by step instructions to correct this and a clear explanation for this happening. I am using windows 7 64 bit. and the computer is a desk top. I can go to any other web site I choose but not yahoo.com. ?? Thank you, I await your favorable reply.