Not all updates that Windows receives are good, especially in the month of January when due to the Christmas holidays they do not receive all the evidence needed to get them into production. And in this case, the January update is causing problems between users.
January update causes problems for users using an L2TP VPN
Users have started report that after installing the January update known as KB5009543 on Windows 10 and KB5009566 in Windows 11, your computers are unable to connect to any type of VPN L2TP giving an error code when trying.
The error is that after trying connect to an L2TP VPN, the following occurs Error code: The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.
How to fix this problem on Windows
For this problem there may be two solutions. The first solution would be to disable the Vendor ID, as Microsoft clarifies: “To mitigate the problem on some VPNs, you can disable the Vendor ID in the server settings. Note: Not all VPN servers have the option to disable the use of the provider ID»
Other solution, which is probably the simplest is temporarily uninstall the update and pause updates until Microsoft fixes the problem. We show you how you can do it in a simple way:
- We right click on the start button, and click on Windows Terminal (Admin) or Windows Powershell (Admin) depending on the version of Windows you are on.
- Once we are inside, we copy the following command depending on your operating system:
- Windows 10: wusa /uninstall /kb:5009543
- Windows 11: wuse /uninstall /kb:5009566
- When the uninstall process is finished, we restart the computer.
- We’re going to Settings > Windows Update or Settings > Update & Security > Windows Update, and click on pause updates. In this way we will prevent the update from being installed again, until Microsoft solve the problem.