When trying to enter https://stackexchange.com/users/login I get the 'This connection is untrusted' warning from Firefox. I'm currently using internet explorer to ask this question. I have no trouble in accessing http://stackexchange.com/ with Firefox, though.
In the details section:
stackexchange.com uses an invalid security certificate. The certificate is not trusted because it was signed using a signature algorithm that was disabled because that algorithm is not secure. (Error code: sec_error_cert_signature_algorithm_disabled)
If I try to add the exception, I still cannot access the page. Below is the info on the certificate exception I added.
Any help would be appreciated.