WHAT IS THE SSL CERTIFICATE NAME MISMATCH ERROR?
This error message warns off customers because it could mean that phishers are trying to pass a malicious website as your legitimate site.
It occurs if the domain name in the SSL certificate doesn’t match the address in the address bar of the browser.
As a web administrator you could forward all visitors to the www. address from the https:// one and purchase an SSL certificate with the www. address as the domain name.
Are you accessing a server using an internal name? If the certificate only has the public name on it, it could cause the name mismatch error. Again, a SAN or UC certificate will solve your problem by including both names on the certificate.