ppp and openvpn Can't create interface

I have installed in one oportunity the openvpn and unninstalled it because the interfaces tun are not created.

So i tryed with ppp but the same problem, the interface ppp is not created.

I followed the step by step of this tutorial
georgetasioulis.com/how-to-install-and-configure-pptp-vpn-on-a-cpanel-server/

And on the csfpre.sh i pasted this:

iptables -A INPUT -i venet0 -p tcp --dport 1723 -j ACCEPT
iptables -A INPUT -i venet0 -p gre -j ACCEPT
iptables -A OUTPUT -p gre -j ACCEPT
#iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -t nat -A POSTROUTING -s 192.168.50.0/24 -j SNAT --to-source ww.xx.yy.zz
iptables -A FORWARD -i ppp+ -o venet0 -j ACCEPT
iptables -A FORWARD -i venet0 -o ppp+ -j ACCEPT

My server is a centos server version 6.8 with Cpanel & Whm and CSF

Thanks in advance