Windows admins report that the September 2026 cumulative updates are causing Remote Desktop Services (RDS) failures on Windows Server 2019, 2022, and 2025 systems, preventing users from connecting and, in some cases, requiring a hard reset to restore functionality.
The problems appear after installing this month's Microsoft September 2026 Patch Tuesday cumulative updates, with many admins reporting on Reddit [1, 2, 3] that RDS servers work normally for a few hours before connections start failing.
Once a server starts failing, existing Remote Desktop sessions may not be able to disconnect or log off properly. New connection attempts can also hang during the connection process and eventually fail.
Hanging Remote Desktop connectionSource: Reddit
BleepingComputer has also received reports from readers who say their Terminal Servers began experiencing similar problems after installing the September updates.
