VPN connection

I am having trouble with a VPN connection it says it cannot be connected.

Using the L2TP with pre-shared key and username / password.

The issue is the network connection between your computer and the vpn server could not be established.

Can anyone help me with this?

I have a PC which can connect to the VPN and i copied all the settings including opening the port in the firewall. but it still doesnt work.