This is a warning, not an error, and is entirely normal and nothing to worry about.
The certificate warning you are receiving simply says that the name in the SSL certificate on the server doesn't match the domain you're logging in with. This is merely to warn you that you may in fact be logging into a different website than the one you're expecting, if you expected a valid certificate.
In English, each of our servers has an SSL certificate generated against the hostname, for example server.eicra.com. When you log in to your websites control panel (www.yourdomain.tld/cpanel), it checks the certificate against your domain name and sees that they do not match (for example www.yourdomain.tld does not match server.eicra.com) and warns you accordingly.
Despite the warning, you are logging into the correct server and this should be ignored. Unfortunately we cannot generate SSL Certificates for each domain we host, so this warning cannot be prevented.
Some customers have issues with getting SSL certificate warnings when trying to login and access Cpanel. The security error which you see is due to accessing a URL in which the name of the site does not exactly match the domain to which we had put on our SSL certificate. As an example, "server.eicra.com" would be listed on the certificate as your server. However, when you log into control panel, your connection usually will go to "server.eicra.com". This is the reason for the mismatch error.
Depending on the security settings in your browser, this message can be triggered. This connection is still secure. The warning is just letting you know of the difference in the name.
You may stop the error messages by permanently accepting the server certificate which will work fine until the cert is renewed which is done annually. In Internet Explorer, choose to continue to web site. Once logged in, right click on the page and choose Properties from the menu. Click on the Certificates button. Click on the Install certificate button. Follow the rest of the wizard.
Next time when you receive the message, select the "Accept the certificate permanently" and you should not be alerted to this issue again.
In Firefox 3, you may be warned with a security message box when trying to login to your cPanel account for your domain. In the message it will say something to the effect of:
server.lunarpages.com:2083 uses an invalid security certificate.
The certificate is not trusted because it is self signed.
(Error code: sec_error_untrusted_issuer)
To get rid of this error message, on the bottom of the screen you should see a button that says, "Add Exception...". Click that and another box should pop up. On that box, you should see the words "Add Security Exception".
"The site's security certificate is not trusted!" To get rid of this error message, click "Proceed Anyway".
"Authentication failed because the server certificate is not trusted." You may stop the error messages by clicking "Continue".
Click on the "Get Certificate" button and then make sure the check mark box for "Permanently store this exception" is checked. On the bottom of the popup window click on Confirm Security Exception. Now it will ask you to confirm. A new box pops up telling you the information must be resent to try to login again - click the "Resend" button and you are done.