Went from 16.04, connecting to VPN fine through Network Manager on Xenial. Under 18.04 it doesn't connect, settings are unchanged. Get the grey icon which vanishes after 10 seconds. I've tried the 'use password for all users option' which some people have used, doesn't work for me.
Update: from looking at system logs I saw UFW block. When disabling the firewall I can connect to the VPN.
My question: is it safe to use VPN with the firewall disabled? This is a remote PC connecting to windows terminal services. And secondly can I add an exception so the gateway is accepted and not blocked?