Windows 11, version 23H2 known issues and notifications

Find information on known issues and the status of the Windows 11, version 23H2 rollout. For immediate help with Windows update issues, click here if you are using a Windows device to open the Get Help app or go to support.microsoft.com. Follow @WindowsUpdate on X (formerly Twitter) for Windows release health updates. If you are an IT administrator and want to programmatically get information from this page, use the Windows Updates API in Microsoft Graph.

• 

  How to get the Windows 11 2026 Update

• 

  An IT pro’s guide to Windows 11, version 26H2

Known issues

Issue details

September 2026

USB audio devices might fail to start or produce no sound

After installing the September 8, 2026, Windows security update (KB5122880), some USB Audio Class 1.0 devices might fail to start or produce audio. Affected devices might experience one or more of the following symptoms: 

• ​The device displays an error in Device Manager: "This device cannot start (Code 10).” 
• ​No audio output.
• ​Volume controls are unresponsive or remain at zero. 
• ​Sound settings are unresponsive or unavailable. 
• ​Some devices might function in standard stereo configurations but fail when using multichannel audio features, including 8-channel or 3D audio modes. Some customers have reported that they're able to restore audio in these cases by switching to 2-channel mode. (*Note: This behavior is resolved in the out-of-band update released on September 14, 2026. See Resolution section below.)

This issue is limited to USB Audio Class 1.0 devices.

Microsoft Support: IT administrators who need an immediate workaround for the symptoms not addressed yet by the OOB update should contact Microsoft Support for Business for assistance. 

Resolution: This issue is partially resolved in the out-of-band (OOB) update released on September 14, 2026, (KB5129242), and updates released after this date. This OOB update resolves the symptoms experienced on devices using 8-channel or 3D audio modes (last bullet point in the list of symptoms documented in this entry). We are working to address the other symptoms and will update this documentation when more information is available. 

Affected platforms:

• ​Client: Windows 11, version 26H2; Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016
• ​Server: Windows Server 2025; Windows Server 2022; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012

Remote Desktop Services might stop responding after Sept. 2026 security update

After installing the September 2026 Windows security update (KB5122880), some organizations might experience issues with Remote Desktop Services (RDS).

In some environments, RDS might become unstable, resulting in RDP connections failing after several minutes, sign-in issues, or servers hanging at "Please wait for the Remote Desktop Configuration". Related tools, including Microsoft Management Console (MMC), RDS Licensing Diagnoser, and File Explorer might also become unresponsive. Additionally, the Windows Update page might stop responding and continuously display a loading indicator. 

Note: This issue does not affect Windows 365 or Azure Virtual Desktop.

Resolution: This issue is resolved by the out-of-band (OOB) update released on September 14, 2026 (KB5129242), and in updates released after this date.

IT administrators who deployed a temporary mitigation through Group Policy do not need to take any action before installing this OOB update.

This OOB update is cumulative and includes all improvements and security protections contained in previous Windows updates. As a best practice, we recommend installing the latest update available for your devices, as it contains important improvements and issue resolutions, including this one.

Affected platforms:

• ​Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016
• ​Server: Windows Server 2025; Windows Server 2022; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012

Host folder shares might be unavailable in Hyper-V-based Linux VMs

Updated (9/14): The resolution section was updated. IT administrators that deployed a temporary mitigation through Group Policy must re-enable the Group Policy and install the out-of-band update to resolve the issue.

After installing the September 2026 security update KB5122880, applications that use HCS-managed virtual machines might experience issues when sharing host folder with Linux VMs using Plan9. Affected virtual machines start normally, but folders shared from the Windows host using Plan9 do not appear or cannot be accessed in the guest environment.

Applications or sandbox environments that depend on these shared folders might display an error indicating that no Plan9 drive shares were mounted. Claude Cowork and the Windows Subsystem for Linux (WSL) are two of the applications affected by this issue. Standard Hyper-V virtual machines that do not use the Plan9 feature are not affected by this issue.

Resolution: This issue is resolved by the out-of-band (OOB) update released on September 14, 2026 (KB5129242), and in updates released after this date.

IT administrators who deployed a temporary mitigation through Group Policy must re-enable the Group Policy, install this OOB update, and restart to resolve this issue.

This OOB update is cumulative and includes all improvements and security protections contained in previous Windows updates. As a best practice, we recommend installing the latest update available for your devices, as it contains important improvements and issue resolutions, including this one.

Affected platforms:

• ​Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2
• ​Server: None

Click here to manage email notifications for Windows known issues. 

August 2026

Incorrect notifications that "Microsoft Defender Antivirus is turned off"

After installing Microsoft Defender Antivirus update (version 4.18.26070.9), released on August 5, 2026, notifications might appear stating that "Microsoft Defender Antivirus is turned off," even though the antivirus is functioning correctly and all settings show it as active. These notifications can appear when Windows starts and intermittently afterward. They persist even if notification settings are turned off.

This issue can be observed in any version of Windows or Windows Server with Microsoft Defender Antivirus running with the latest Defender updates.

Resolution: This issue was resolved in Microsoft Defender Antivirus update (version 4.18.26080.4), released on September 17, 2026.

Affected platforms:

• ​Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016
• ​Server: Windows Server 2025; Windows Server 2022; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012

Report a problem with Windows updates

To report an issue to Microsoft at any time, use the Feedback Hub app. To learn more, see Send feedback to Microsoft with the Feedback Hub app.

Need help with Windows updates?

Search, browse, or ask a question on the Microsoft Support Community. If you are an IT pro supporting an organization, visit Windows release health on the Microsoft 365 admin center for additional details.

For direct help with your home PC, use the Get Help app in Windows or contact Microsoft Support. Organizations can request immediate support through Support for business.

View this site in your language

This site is available in 11 languages: English, Chinese Traditional, Chinese Simplified, French (France), German, Italian, Japanese, Korean, Portuguese (Brazil), Russian, and Spanish (Spain). All text will appear in English if your browser default language is not one of the 11 supported languages. To manually change the display language, scroll down to the bottom of this page, click on the current language displayed on the bottom left of the page, and select one of the 11 supported languages from the list.