Certificate issuer expired message when trying to sign up for online billing

[jetski]

Hi,

I am trying to sign up for online billing, but I get the following message from Firefox

www2.bt.com uses an invalid security certificate.

The certificate is not trusted because the issuer certificate has expired.

(Error code: sec_error_expired_issuer_certificate)

wierdly IE seems happy (the URL is different, persumably re-directed) please can you check out why Firefox is unhappy?

[paragon123]

It means that the browser does not have the certificate of that particular site. If you are really sure on that website, you can just go ahead and ignore the warning and you have the option to add the certificate in your browser. 

Could also be malicious if you haven't heard of that before. Good luck.