Somewhat an odd situation here. I am using Private Internet Access on my Mac. I am also using a Windows VM on Parallels to do some work for my clients. One of the clients requires a VPN connection to their network, which is set up through Windows as a new VPN connection. When Private Internet Access VPN client is disconnected, Windows VPN connection connects with no issues. However, when the client is connected, Windows VPN connection goes through all the steps, then hangs on "Verifying User name and Password" message for about 20 seconds before giving up.
The workaround to the problem was to change network configuration for Parallels VM from Shared to Bridged.