VPN tunnel with Advantech router

Hello I'm having trouble creating a VPN tunnel to my Windows server from a Advantech router. I'm trying to make a VPN PPTP connection from a Advantech ICR-2431W router to my Windows server 2016 server. The Windows server is in this case the VPN server and the router client. The problem I have is with the authentication part of the connection. This connection works with a SIM card over 4G. Before I was using Teltonika routers but these routers does not have some options that I need what the Advantech does have. Error from Windows server CoId={NA}: The user **** connected from 127.0.0.1 but fail

Question by Dylan D on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.