I recently upgraded to Windows 10 and came across an issue where Windows 10 VPN would not connect to my Windows RRAS Server.
While setting up the VPN to connect to my Windows RRAS server I got a connection error even though the VPN worked fine on my Windows 7 clients.
How to Fix the Windows 10 VPN Connection Issue
The fix for my RRAS connection was related to an authentication issue.
To start create and save the VPN connection even if it won’t connect because we need to have that VPN connection saved.
Now go into the Control Panel, select ‘Network and Internet‘ and then ‘Change Adapter Options‘
Right-click on the VPN adapter with the connection issue and select Properties
Select the “Security” tab and then change the authentication from EAP to “Allow these protocols” and make sure MS-CHAP V2 is check-marked and you should be all set.
Once your authentication settings are adjusted Windows 10 should connect to your RRAS server without issue
Note: I have also had instances where I need to change the VPN type to PPTP rather than the “automatically detect” but this depends on which Windows Server you have and how the authentication is configured
