Ubuntu 18.04 VPN Connection

I have a problem with the GUI network-manager for VPN. When I use it I get an error message:

unable to load VPN network connection editor

If I use the terminal it works. How can I get the network GUI to work?. Any ideas?.

I have just had the same problem which I fixed. I was attempting to add an OpenVPN connection (you haven't stated which type of VPN you're using) but the idea will work. I already had openvpn and network-manager-openvpn installed via apt, but I needed to add network-manager-openvpn-gnome

sudo apt install network-manager-openvpn-gnome

then restarted network manager (this kills networking until it's fully restarted)

sudo service network-manager restart

After this, I could open system settings again, go to networking and add my OpenVPN stuff.

This has been an issue for a couple of years and was answered here: Unable to load VPN connection editor in Ubuntu 14.04 LTS

Cheers