I am trying to connect from a Windows 10 client to an Ubiquiti EdgeRouter VPN, I went through the instructions on https://help.ubnt.com/hc/en-us/articles/204950294-EdgeRouter-L2TP-IPsec-VPN-Server but whenever I try to connect to the VPN I get the following:
Can't connect to The L2TP connection attempt failed because the security layer could not negotiate compatible parameters with the remote computer.
I did some research and changed the VPN security properties to allow Microsoft CHAP Version 2 (MS-CHAP v2) and also Challenge Handshake Authentication Protocol (CHAP) but it didn't seem to make a difference at all.
At the same time I have no problems whatsoever to connect from a macOS High Sierra client. So my guess is that there is something wrong on the client side (Windows VPN settings)? Can anybody help me out with this?