Issues with Microsoft Windows September 2026 Update

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Article ID: CTX697101

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Updated On:

Description

Reported issues currently include:

1) New connections start hanging a few hours after reboot with "Connecting..." and existing users are unable to log off

The following signatures are indicative of this particular issue:

  • TerminalServices-RemoteConnectionManager Event 20498: “Remote Desktop Services has taken too long to complete the client connection”
  • Winlogon Event 6005: “The winlogon notification subscriber SessionEnv is taking long time to handle the notification event (Disconnect)”
  • TermService status: StopPending rather than Running

2) Black Screens on Login after installing KB5124008 / KB5120998 on Desktop OS VDAs

Resolution

To address 1st issue (New connections start hanging a few hours after reboot with "Connecting..." and existing users are unable to log off):

Microsoft has released out-of-band (OOB) patches to remediate the Remote Desktop Services (RDS) issue. The relevant patches are listed below. 
 

  • Windows 11, versions 25H2 and 24H2: KB5129195  
  • Windows 11, versions 25H2 and 24H2 (hotpatch): KB5129241  
  • Windows 10, version 22H2 and Windows 10 Enterprise LTSC 2021: KB5129236  
  • Windows 10 Enterprise LTSC 2019 and Windows Server 2019: KB5129238  
  • Windows 10 Enterprise LTSB 2016 and Windows Server 2016: KB5129239  

*Customers on older platforms will be supported as per their extended support considerations. 

To download the required patches, sign in to the Microsoft catalog update page, search for the relevant KB number, download the patch, install and reboot the machine. 

 

Please note: With respect to 2nd issue mentioned above (Black Screens on Login after installing KB5124008 / KB5120998 on Desktop OS VDAs):

Even after applying above OOB updates, environments using Citrix Virtual Apps and Desktops (CVAD) in combination with profile management solutions like Citrix UPM or FSLogix can still exhibit the issues. This behavior is documented by Microsoft in the Windows 11, version 24H2 release health status page. Customers are encouraged to contact Microsoft for any further guidance and support.

 

If there are further updates, we will modify this article.  

Issue/Introduction

Citrix is actively monitoring multiple reported issues following the installation of the Windows September 2026 Rollup Update on Windows Server and client OS based Virtual Delivery Agents (VDAs).

Windows OS KB Build
Server 2016 KB5123099 –
Server 2019 KB5122876 –
Server 2022 KB5122882 20348.5622
Server 2025 KB5122871 26100.33438
Windows 11 KB5124008  
Windows 11 KB5120998