Each day we read the Known issues section of Microsoft's support article for every recent Windows and Office update and record what changed. Since our last post, Microsoft changed that section on 4 updates. Every quote below is Microsoft's own text, from the article linked beside it.
Known issues Microsoft updated
"USB Audio Class 1.0 devices with error Code 10 or no output"
Microsoft changed the text of this known issue for:
- KB5129194 (Windows 11 version 26H1 and Windows 11 Version 26H1), Microsoft's article
- KB5129241 (Windows 11 Version 25H2 and Windows 11 Version 24H2), Microsoft's article
The new text, in Microsoft's words:
After installing the September 8, 2026, Windows security update, 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. This issue is limited to USB Audio Class 1.0 devices. Microsoft is working on a resolution and will update this documentation when more information is available.
"Change log"
Microsoft changed the text of this known issue for:
- KB5129241 (Windows 11 Version 25H2 and Windows 11 Version 24H2), Microsoft's article
The new text, in Microsoft's words:
| | Change date | Change description | September 25, 2026 | Known issues added: • Devices might experience a black screen or desktop loading issues after sign-in.
"Domain-joined devices might lose their secure trust relationship with the domain"
Microsoft changed the text of this known issue for:
- KB5129241 (Windows 11 Version 25H2 and Windows 11 Version 24H2), Microsoft's article
The new text, in Microsoft's words:
Users might then be unable to sign in interactively with valid domain credentials and might receive a message stating that the trust relationship between the device and the domain failed. Offline sign-in using previously cached credentials might continue to work. AD replication and AD services on the domain controllers are not affected. This issue occurs because KB5124008 and later updates enable the Machine Identity Isolation feature. While the update does not directly enable Machine Identity Isolation enforcement, it does cause Windows to begin honoring any existing or policy-provisioned settings that enabled Machine Identity Isolation enforcement. However, this feature is only supported for environments connected to domain controllers running at a Windows Server 2025 Domain Functional Level (DFL) and above. The feature should be disabled elsewhere. Any devices previously configured to use Machine Identity Isolation that are not connected to Windows Server 2025 domain controllers will experience this issue and will need to disable the feature. Important: This section contains information about modifying the registry. Before you modify the registry, back it up and make sure that you know how to restore it if a problem occurs. For more information, see How to back up and restore the registry in Windows . To work around this issue, disable Machine Identity Isolation using the same management method that was used to enable it. Choose the applicable option below: If Machine Identity Isolation was enabled by Intune policy, disable Machine Identity Isolation with Intune . If Machine Identity Isolation was enabled by Group Policy, disable Machine Identity Isolation with Group Policy . If Machine Identity Isolation was enabled directly in the registry, use these steps to disable it: On the Windows 11, version 24H2 or 25H2 device, locate the following registry paths: HKLM\SYSTEM\CurrentControlSet\Control\Lsa\MachineIdentityIsolation HKLM\SOFTWARE\Policies\Microsoft\Windows\DeviceGuard\MachineIdentityIsolation For either of these registry keys, if the value of MachineIdentityIsolation is set to 2 , change it to: MachineIdentityIsolation = 0 After you disable Machine Identity Isolation, restart the device. Then reset the secure channel using the following command: Test-ComputerSecureChannel -Repair -Credential (Get-Credential) Microsoft plans to resolve this issue in a future Windows update by temporarily preventing Machine Identity Isolation enforcement while improvements are made to the feature.
"File History might stop working after installing September 2026 Windows update"
Microsoft changed the text of this known issue for:
- KB5129194 (Windows 11 version 26H1 and Windows 11 Version 26H1), Microsoft's article
The new text, in Microsoft's words:
After installing the September 2026 Windows security update KB5124008 , some customers using File History, might be unable to create or update backups. File History, available through Control Panel > System and Security > File History , is used to back up files to an external drive or network location. Affected devices might incorrectly display a "Reconnect your drive" message even when a compatible backup drive is connected and functioning properly. Additionally, the "Last Backup" timestamp might not update, and previously backed up files might show "No previous version available." In some cases, Event Viewer might record application crash events referencing FileHistory.exe and KERNELBASE.dll . This issue is resolved in Windows updates released on and after September 22, 2026 such as KB5124006 .
"File History might stop working after installing September 2026 Windows update"
Microsoft changed the text of this known issue for:
- KB5129241 (Windows 11 Version 25H2 and Windows 11 Version 24H2), Microsoft's article
The new text, in Microsoft's words:
After installing the September 2026 Windows security update KB5124008 , some customers using File History, might be unable to create or update backups. File History, available through Control Panel > System and Security > File History , is used to back up files to an external drive or network location. Affected devices might incorrectly display a "Reconnect your drive" message even when a compatible backup drive is connected and functioning properly. Additionally, the "Last Backup" timestamp might not update, and previously backed up files might show "No previous version available." In some cases, Event Viewer might record application crash events referencing FileHistory.exe and KERNELBASE.dll . Microsoft is working on a resolution for this issue in a future Windows update and will provide more information when it is available. How to get this update Before you install this update Microsoft combines the latest servicing stack update (SSU) for your operating system with the hotpatch update. For general information about SSUs, see Servicing stack updates . If you are using Windows Update, the latest SSU installs with this update. Install this update To install this update, use one of the following Windows and Microsoft release channels. | | Release Channels | Available | Next step | Windows Update | | This update downloads and installs automatically from Windows update. | Catalog | | See the other options. | Server Update Services | | See the other options. File information For a list of the files provided in this update, download the file information for the out-of-band hotpatch update KB5129241 . For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5124007) - version 26100.9441 .
"Microsoft Teams and Outlook might fail to launch on ARM-based devices"
Microsoft changed the text of this known issue for:
- KB5121003 (Windows 11 Version 25H2 and Windows 11 Version 24H2), Microsoft's article
The new text, in Microsoft's words:
We recommend you install the latest Windows update for your device as it contains important improvements and issue resolutions, including this one.
"Remote Desktop connections might fail for non-admin users with error 0xC000000D"
Microsoft changed the text of this known issue for:
- KB5127646 (Windows 11 Version 26H1 and Windows 11 version 26H1), Microsoft's article
The new text, in Microsoft's words:
After installing the September 2026 non-security preview update KB5124006 , or later updates, non-admin users might be unable to establish Remote Desktop connections to remote devices that have Administrator protection enabled.
Every recent update and its known issues are on our Microsoft patch tracker.
Compiled automatically by the Senserva Patch Tracker from Microsoft's support articles. No AI writes this post: every quote is copied from the article it links, and an issue counts as changed only when Microsoft's text changed. Sources and their terms are on our Data sources & thanks page. Facts as of 2026-10-24.