Hostname u'xx.xx.xx.xx' doesn't match certificate domain(s)

applaud

Before I purchase the actual certificates I am testing them with trial version of COMODO certificates.
When I try to verify the certificates I am getting following warning for Hostname verification.

Hostname u'xx.xx.xx.xx' doesn't match certificate domain(s): hostname.example.com, www.hostname.example.com

I requested the certificate for CN: hostname.example.com instead of host IP.
Is it not possible to have a domain name as CN for Access server?

applaud

I just updated the "Hostname or IP Address:" to my domain name, after that certificates are verified successfully.