Hi,
Following the instructions in this post, will probably resolve that:
First off I would save the current rules:
sudo netfilter-persistent save
Then I would disable iptables-restore:
sudo systemctl disable netfilter-persistent
Then reboot. Hopefully openvpn and ntp are now up.
If that is the case, you can now restore iptables:
sudo systemctl enable netfilter-persistent
sudo systemctl start netfilter-persistent
Thanks Tom.