I've got PPP VPN set up on my Cisco and my Win7 clients can connect to it without any issue, however my Win10 clients all get authenticated then the message "The PPP link control protocol was terminated" is displayed.

Link Control Protocol (LCP) Frames. The link control protocol (LCP) frames are transmitted during the link establishment and termination phases, and periodically during the life of the link. They are used to negotiate the configuration of the PPP link, and to test and maintain the link, once it is established. Error 734 PPP link control protocol was terminated Jun 01, 2012 What is the Point-to-Point Protocol and how does it work Mar 09, 2017

Aug 16, 2013

PPP link control protocol was terminated - Internet

Aug 16, 2013

Win10 VPN PPP link terminated - Networking Jan 18, 2016 Common VPN Error Codes – HMA Support Jul 10, 2020 Error 734: PPP link control protocol was terminated Dec 22, 2013