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.
For example, if the certificate is for www.SSL247.co.uk, but a user access the site using https://SSL247.co.uk (without the www.) they’ll get the Name Mismatch Error.
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.
However the best solution is a SAN certificate. This allows you to get https://SSL247.co.uk a certificate but also provide a SAN for www.SSL247.co.uk so both are secured with the one certificate.
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.