Restore firewalld.service file contents.

[root@idmipa01 ~]# systemctl enable firewalld
Failed to execute operation: Operation not supported
[root@idmipa01 ~]# 

[root@idmipa01 ~]# systemctl enable firewall
Failed to execute operation: Access denied
[root@idmipa01 ~]# 

[root@idmipa01 system]# vi firewalld.service
[root@idmipa01 system]# systemctl enable firewalld
Created symlink from /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service to /usr/lib/systemd/system/firewalld.service.
Created symlink from /etc/systemd/system/basic.target.wants/firewalld.service to /usr/lib/systemd/system/firewalld.service.
[root@idmipa01 system]# systemctl start firewalld
[root@idmipa01 system]#
[root@idmipa01 system]#
[root@idmipa01 system]#
[root@idmipa01 system]# cat firewalld.service
[Unit]
Description=firewalld – dynamic firewall daemon
Before=network.target
Before=libvirtd.service
Before=NetworkManager.service
Conflicts=iptables.service ip6tables.service ebtables.service

[Service]
EnvironmentFile=-/etc/sysconfig/firewalld
ExecStart=/usr/sbin/firewalld –nofork –nopid $FIREWALLD_ARGS
ExecReload=/bin/kill -HUP $MAINPID
# supress to log debug and error output also to /var/log/messages
StandardOutput=null
StandardError=null
Type=dbus
BusName=org.fedoraproject.FirewallD1

[Install]
WantedBy=basic.target
Alias=dbus-org.fedoraproject.FirewallD1.service
[root@idmipa01 system]#