(10-14-2015, 01:43 PM)TGates Wrote: If you are not using Sentora DNS, we may not be able to help you much as this is what we are familiar with.
Double check what your settings are for your working sub domains (in the panel, your DNS server and domain registrar) and compare them to the non-working sub domains. Also check your httpd-vhosts.conf file and see if any entries are there for your working or non-working sub domains.
Thank You TGates! Your reply helped me to sort-out the issue. It was the problem of 3rd party DNS settings.