A service alert from Microsoft warns that deployments of the September 2026 Windows 11 security updates are causing Always On VPN connection problems for enterprise users. The remote access solution, which serves as a successor to DirectAccess, supports domain-joined systems, non-domain-joined machines, and Microsoft Entra ID–joined devices across Windows 10, Windows 11, and Windows Server platforms.
Always On VPN operates by automatically establishing a secure tunnel to corporate networks whenever a device connects to the internet. The technology enables administrators to control which applications and services can route traffic through the VPN and supports modern protocols including IKEv2 and SSTP alongside multi-factor authentication capabilities.
According to the alert shared by Microsoft MVP Susan Bradley, the problem emerges when VPN configurations are set to automatically attempt alternative connection methods if the primary attempt fails—such as automatic protocol selection between IKEv2 and SSTP.
This issue can occur when the VPN is configured to automatically try another connection method if the initial connection fails (for example, when using automatic protocol selection with IKEv2 and SSTP). Affected VPN connections might remain in a 'Connecting' state or repeatedly attempt to connect without succeeding. Subsequent connection attempts might also display the error: 'The specified port is already in use.'
Microsoft
Temporary Mitigation Available
While Microsoft develops a permanent resolution, the company has released interim guidance for affected organizations. The workaround involves disabling automatic protocol selection in Always On VPN profiles.
IT administrators can mitigate this issue by changing the Always On VPN profile from automatic protocol selection to a single protocol, either SSTP only or IKEv2 only, depending on their environment and configuration. Organizations should select the protocol based on their environment, security, and deployment requirements.
Microsoft
Broader Update Issues Continue
The Always On VPN problem represents one of several issues tied to this month's cumulative updates. Microsoft released emergency patches seven days earlier to address Hyper-V failures, Remote Desktop Services malfunctions, and USB audio problems all stemming from the September 2026 updates.
Additional known issues include a bug preventing some Windows 11 users from authenticating with valid domain credentials and a separate defect causing the built-in File History backup feature to cease functioning. Microsoft stated it is actively working to resolve both problems.