The error message ssl_error_access_denied_alert means that the access to the website you are trying to visit is denied due to the SSL error. This error can also occur even if the SSL certificate of a website is valid. Hence, it does not conclude that the SSL certificate of that particular website is expired or not valid. You will see this error message usually when the authenticity of the data received for a website is not verified. To fix this error, type about:config in the address bar of Firefox and hit Enter. Now, click Accept the Risk and Continue. Search for security.tls.version.max and change its value from 4 to 3.