I assume Firefox developers did something wrong with last release (43.0.1) since I get this error after installing updates:
This Connection is Untrusted
You have asked Firefox to connect securely to www.google.com, but we can't confirm that your connection is secure.
Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified.
What Should I Do?
If you usually connect to this site without problems, this error could mean that someone is trying to impersonate the site, and you shouldn't continue.
This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox only connect to it securely. As a result, it is not possible to add an exception for this certificate.
Get me out of there
www.google.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)
I would like to emphasize that everything worked before the update. Also right after update the new version screen advertised new and better security.
My question is "How do I fix this?" - unless I am actually trying to connect to fake google server. Is something wrong with my computer, so suddenly?