The Update BureauWindows 11, version 26H2 · Release Health
Known issues in Windows 11, version 26H2
Problems Microsoft has confirmed for this version, from its official release health notes. 1 still open or mitigated.
Active known issues
Open & Mitigated-
November security update might fail to install on some devices
Some devices might repeatedly try to install the November security update or show error 0x80070306, 0x800f0989, or 0x800f0993.
Workaround status No workaround yetMicrosoft has not published a manual workaround for this issue yet. Defer KB5132061 on affected systems until a fix is released.
Recently resolved
Fixed in latest updates-
USB audio devices might fail to start or produce no sound
Some USB Audio Class 1.0 devices might fail to start or produce no sound. The 8-channel and 3D audio symptoms are resolved by KB5129194; KB5132059 and later updates resolve the remaining symptoms.
How to apply the workaround WorkaroundSome customers reported restoring audio in multichannel cases by switching to 2-channel mode.
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Remote Desktop connections might fail for non-admin users with error 0xC000000D
Non-admin users might fail to connect to Remote Desktop hosts with Administrator protection enabled, seeing error 0xC000000D. KB5127653, released October 27, 2026, resolves this issue.
How to apply the workaround Group Policy / IntuneOn affected devices using an update from before October 27, 2026, temporarily turn off Administrator protection by resetting the User Account Control Type Of Admin Approval Mode policy in Intune or Group Policy.
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File History might stop working after installing September 2026 Windows update
Some File History users might be unable to create or update backups, even when a working backup drive is connected. Updates released on or after September 22, 2026, such as KB5124006, resolve this issue.
Resolution Fixed in KB5126653Install KB5126653 (or a later cumulative update) on affected devices. No manual workaround is required after updating.
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Devices might experience a black screen or desktop loading issues after sign-in
Some devices, primarily Azure Virtual Desktop hosts using FSLogix, might show a black screen after sign-in or fail to load the desktop automatically. This issue is resolved by updates released October 13, 2026, including KB5127648.
How to apply the workaround Group PolicyBefore installing the resolving update, users can start Explorer manually; enterprise IT can mitigate the issue with Known Issue Rollback and a restart.
Step-by-step workaround instructionsShow steps Hide steps2 stepsStep-by-step procedure- To temporarily start the desktop, open Task Manager, select Run new task, enter
explorer.exe, and select OK. - For enterprise-managed devices, install and configure the applicable Known Issue Rollback Group Policy, then restart the devices.
- To temporarily start the desktop, open Task Manager, select Run new task, enter
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Applications which require AC-3 audio decoding might close unexpectedly
Some applications that rely on Windows built-in AC-3 (Dolby Digital) audio decoding might fail to launch or close unexpectedly when certain audio features are used. KB5127648 and later updates resolve this issue.
Resolution Fixed in KB5127648Install KB5127648 (or a later cumulative update) on affected devices. No manual workaround is required after updating.
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You might be unable to turn on Smart App Control
Some devices cannot turn Smart App Control back on after it was turned off; its setting might be grayed out.
How to apply the workaround Registry / GPOThe values restore the ability to turn on Smart App Control.
Step-by-step instructions, command & download kitShow steps & kit Hide steps & kit3 steps cmd.exe · Administrator Power-User Kit (.zip)Step-by-step procedure- Back up the registry before making changes.
- Open Command Prompt as an administrator and run both commands.
- Restart the device.
> reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" /v 2883193997 /t REG_DWORD /d 1 /f> reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" /v 2850574478 /t REG_DWORD /d 1 /f
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Domain-joined devices might lose their secure trust relationship with the domain
Some Credential Guard protected machine accounts might lose their secure connection to an on-premises domain, blocking interactive sign-in. KB5124006 and later updates resolve this issue.
How to apply the workaround Group Policy / IntuneThe rollback or disabling Machine Identity Isolation stops its enforcement, which prevents the affected domain trust problem. The rollback policy must be set to Disabled, and the device must be restarted.
Step-by-step instructions, command & download kitShow steps & kit Hide steps & kit4 steps powershell.exe · Administrator Power-User Kit (.zip)Step-by-step procedure- For the rollback option, install the special Group Policy for Windows 11, version 26H1, set its KB5124012 rollback policy to Disabled, and restart the devices.
- Alternatively, disable Machine Identity Isolation using the same method that enabled it: Intune policy, Group Policy, or the registry.
- If using the registry, check either listed key. Change
MachineIdentityIsolationfrom 2 to 0 only when its current value is 2. - Restart the device, then repair the secure channel with the PowerShell command.
> Test-ComputerSecureChannel -Repair -Credential (Get-Credential)
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