Iptables – CentOS 7: Fresh Install Firewalld doesn’t work at all (Fatal Error: No IPv4 and IPv6 firewall)

I have the following problem.

I just did an DVD CenOS 7 installation. After I boot into the system I normally login as the root user. From there I'm trying to configure Firewall on my server.

As I'm relatively new to all of this I just did some search on how to start and manage Firewalld which seems to be the intended firewall software to use with CentOS 7.

The first thing I tried was typing

systemctl status firewalld

As output I get

Warning: iptables not usable, disabling IPv4 firewall.
Warning: ip6tables not usable, disabling IPv6 firewall.
FATAL ERROR: No IPv4 and IPv6 firewall.
ERROR: Raising SystemExit in run_server

I already tried rebooting the system, updating it. I reinstalled both iptables and firewalld. Tried it with either of which being masked or disable. None of this has worked but maybe I missed something.

I generally just wanted to setup a Teamspeak server for outside use which worked under Windows when I added a specific rule to the firewall. I wanted to do the same under CentOS 7 mostly for learning purposes or to get familiar with Linux as server at all.