Windows 10: L2TP not connecting on Windows 11 Insider Program

We experience problems with connecting L2TP VPN on a Windows 11 Insider Program workstations. Since the Windows update patch on Tuesday, we managed to solve the VPN connection problems by removing update KB5009543 on Windows 10 and installing update KB5010795 on Windows 11. However we cannot find KB5010795 update for Insider Program workstations. Does anyone know how we can solve this?Below is the error with L2TP VPN connections:Thanks!

:)

 

How to Opt-out of windows insider program?

Hi, I had that problem.. please see

I also made sureSoftwareDistribution\Download was empty.
How to clear the 'SoftwareDistribution' folder on Windows 10 and make updates happen again | Windows Central

Abort pending Windows 11 upgrade

 

Error: 788, when connecting to L2TP VPN

Hi there, recently I got this error when connecting to "L2TP/IPSec with certificate" VPN. I'm not sure what cause this.

I have already follow some of this steps with no luck :

• Adding AssumeUDPEncapsulationContextOnSendRule
• Restarting both IKE and IPSec services
• Allowing both CHAP and MS-CHAP v2
• Reset network connection
• Connect to different provider
• Re-adding VPN settings

There also little bit information can be found in the event viewer :

CoId={AEE0E2A8-34DF-41BB-B5F0-0458EFD41751}: The user xxx\xxx has started dialing a VPN connection using a per-user connection profile named yes. The connection settings are:

Dial-in User = *\

VpnStrategy = L2TP

DataEncryption = Requested

PrerequisiteEntry =

AutoLogon = No

UseRasCredentials = Yes

Authentication Type = PAP

Ipv4DefaultGateway = Yes

Ipv4AddressAssignment = By Server

Ipv4DNSServerAssignment = By Server

Ipv6DefaultGateway = Yes

Ipv6AddressAssignment = By Server

Ipv6DNSServerAssignment = By Server

IpDnsFlags =

IpNBTEnabled = Yes

UseFlags = Private Connection

ConnectOnWinlogon = No

IPsec authentication for L2TP = Machine certificate.

CoId={AEE0E2A8-34DF-41BB-B5F0-0458EFD41751}: The user xxx\xxx is trying to establish a link to the Remote Access Server for the connection named yes using the following device:

Server address/Phone Number = xxx.xxx.xxx.xxx

Device = WAN Miniport (L2TP)

Port = VPN3-1

MediaType = VPN.

CoId={AEE0E2A8-34DF-41BB-B5F0-0458EFD41751}: The user xxx\xxx dialed a connection named yes which has failed. The error code returned on failure is 788.

***Original title: VPN Error 788***

 

Windows 10 L2TP VPN connection issue

I have a Windows 10 client which has been configured to connect to an L2TP VPN.

To get the connection to work, I had to add the "AssumeUDPEncapsulationContextOnSendRule" registry Key, and then totally disable Windows Firewall—the VPN connects perfectly this way.

However, I cannot get the VPN to connect with the Windows Firewall enabled and I really need to keep the Windows Firewall enabled and be able to connect to the L2TP VPN.

I have also allowed...

• Protocol 50 (ESP) in and out
  
• UDP 1701, 4500, 500 in and out
  

However the VPN still only connects if I totally disable the Windows Firewall and not with it enabled.

Question: Any help or guidance suggested to further troubleshoot this problem?