This is usually a configuration error.
First, ensure that named is running and no errors are being reported at startup (/var/log/messages or equivalent). Running named -g <usual arguments> from a title can help at this point.
Secondly, ensure that named is configured to use rndc either by rndc-confgen -a, rndc-confgen or manually. The Administrators Reference Manual has details on how to do this.
Old versions of rndc-confgen used localhost rather than 127.0.0.1 in /etc/rndc.conf for the default server. Update /etc/rndc.conf if necessary so that the default server listed in /etc/rndc.conf matches the addresses used in named.conf. "localhost" has two addresses (127.0.0.1 and ::1).
If you use rndc-confgen -a and named is running with -t or -u, ensure that /etc/rndc.conf has the correct ownership and that a copy is in the chroot area. You can do this by re-running rndc-confgen -a with appropriate -t and -u arguments.