Mozilla Firefox Help

  When Firefox connects to a secure website (the URL begins with "http s ://"), it must verify that the  certificate  presented by the website is valid and that the encryption is strong enough to adequately protect your privacy. If it is unable to verify this, Firefox stops connecting to the site and will show you an error page with the message,  Warning: Potential Security Risk Ahead . What to do if you see these errors? If you see a  Warning: Potential Security Risk Ahead  message, you may: Contact the website owner and ask them to correct their certificate. Click  Go Back (Recommended) , or visit a different website. If you are on a corporate network or using antivirus software, reach out to the support teams for assistance. After viewing the error code and other information about the error, click the  Accept the Risk and Continue  button to load the site at your own risk. This will add a security exception for the website certificate. ...

On websites which are supposed to be secure (the URL begins with "http s ://"), Firefox must verify that the certificate presented by the website is valid. If the certificate cannot be validated, Firefox will stop the connection to the website and show a "Warning: Potential Security Risk Ahead" error page instead. Clicking the   button, you can view the specific error Firefox encountered. This article explains why you might see the error codes SEC_ERROR_UNKNOWN_ISSUER, MOZILLA_PKIX_ERROR_MITM_DETECTED or ERROR_SELF_SIGNED_CERT on an error page and how to troubleshoot it.  Fix Firefox Error What does this error code mean? During a secure connection, a website must provide a certificate issued by a trusted certificate authority to ensure that the user is connected to the intended target and the connection is encrypted. If you click the button on a "Warning: Potential Security Risk Ahead" error page and you see the error code SEC_ERROR_UNKNOWN_ISSUER or MOZIL...