Issue
This is what I got from status firewalld:
firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled)
Active: inactive (dead) since Tue 2015-07-14 02:58:35 UTC; 35s ago
Process: 19546 ExecStart=/usr/sbin/firewalld --nofork --nopid
$FIREWALLD_ARGS (code=exited, status=0/SUCCESS)
Main PID: 19546 (code=exited, status=0/SUCCESS)
Jul 14 02:58:35 li1201-198.members.linode.com firewalld[19546]: 2015-07-14 02:58:35 ERROR: Exception DBusException: org.freedesktop.DBus.Error.AccessDenied: Connection ":1.314" is not allowed to own the service "org.fedoraproject.FirewallD1" due to security policies in the configuration file Jul 14 02:58:35 li1201-198.members.linode.com systemd[1]: Started firewalld - dynamic firewall daemon.
Solution
More recently, Bug 1575845 in Red Hat's Bugzilla tracker shows a problem in RHEL/CentOS 7.3 or later that triggers this issue. Something with dbus policy not being passed correctly. The permanent fix (for now) could be upgrading your base image to a newer version of RHEL/CentOS.
However, these commands should also work, per this comment in the Bugzilla:
sudo systemctl restart dbus
sudo systemctl restart firewalld
Answered By - J.W.F. Answer Checked By - Terry (WPSolving Volunteer)