I always get an error when running cgconfigparser

Question

Here's my /etc/cgconfig.conf:

group VM {
  memory {
    memory.limit_in_bytes = "5G";
    memory.soft_limit_in_bytes = "4G";
  }
}

Here's my /etc/cgrules.conf

#<user:process>                  <controllers>    <destination>
*:/usr/bin/qemu-system-x86_64    memory           VM

but when ever I run cgconfigparser -l /etc/cgconfig.conf, I always get the following error:

/usr/sbin/cgconfigparser; error loading /etc/cgconfig.conf: Cgroup, requested group parameter does not exist

How may I fix this?