Since installing Microsoft's September patch day updates, many users have been unable to establish remote desktop connections to Windows servers. Complaints have been piling up on platforms like Reddit, while Microsoft has not yet commented on the issue.
The bug affects several Windows Server versions: 2019 with update KB5122876, 2022 with KB5122882, and 2025 with KB5122871. After installation, the Remote Desktop Services (RDS) host appears to work normally at first, but freezes after some time.
A deadlock between RDP and the session manager
Several affected users link the problem to user logoffs. As soon as a user logs off, the RDP service apparently stops responding. One user suspects a missing timeout causes a kind of deadlock between RDP and the Local Session Manager (LSM). Other reports confirm the same pattern: a single session disconnect or reconnect that never completes ends up blocking everything else tied to session state on the affected host. Tests in development environments reportedly worked fine, with the disruptions only appearing after a few hours in production.
Only uninstalling helps for good
According to affected users, restarting the server only fixes the problem temporarily, since the RDS host freezes again after the next logoff. So far, the only way to permanently resolve the issue is to uninstall the respective September update. Administrators should keep in mind, though, that doing so reopens the many security vulnerabilities the September patch day closed. Anyone relying on remote desktop access currently has to weigh working remote connectivity against full protection from known vulnerabilities, until Microsoft ships an official fix.