Eu tenho o Firefox 56.0 e o Ubuntu 14.04. No campo URL, eu digito facebook.com que antes me colocaria na página de login do Facebook.
Recentemente, após 2 semanas, sempre recebo este erro e não consigo acessar a página de login do Facebook.
Your connection is not secure
The owner of facebook.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.