Firefox sayst billing.microsoft.com uses an invalid security certificate
I'm trying to close out my hotmail account, but when I try to access billing.microsoft.com, Firefox says that page is using an invalid security certificate because the issuer certificate is unknown, and warns me not to proceed by creating an exception
URL of affected sites
Krejt Përgjigjet (4)
The certificate provided is indeed invalid. It is signed by Microsoft themselves, not a trusted certificate authority.
Apart from that ,latest Google Chrome has the same error message.
This is a root certificate which serves as a website certificate at the same time. This is an oddity, since in all other cases (that I know), you have a root certificate which signs a website certificate.
I wrote more about this at http://certwatch.simos.info/2010/08/0.../the-new-billing-microsoft-com-root-certificate/
It is related to browser settings do,
Firefox -> Tools -> Advanced -> view certificates -> servers -> Add exceptions
and add the your url in that dialogue box.