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Find information on recently resolved issues for Windows 11, version 26H1. To find a specific issue, use the search function on your browser (CTRL + F for Microsoft Edge). 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 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.
Resolved issues
| Summary | Originating update | Status | Date resolved |
|---|---|---|---|
| Devices might experience a black screen or desktop loading issues after sign-in Microsoft has received reports of this issue occurring in some virtual desktop environments. | OS Build 28000.2804 KB5120996 2026-08-27 | Resolved KB5127646 | 2026-10-13 10:00 PT |
| Domain-joined devices might lose their secure trust relationship with the domain Some Credential Guard protected machine accounts might be unable to sign in interactively will valid domain credentials. | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved KB5124006 | 2026-09-22 10:00 PT |
| Incorrect notifications that "Microsoft Defender Antivirus is turned off" Microsoft Defender Antivirus remains active and functioning correctly despite notifications following the latest update. | N/A | Resolved | 2026-09-30 16:42 PT |
| Remote Desktop Services might stop responding after Sept. 2026 security update Some Windows devices with Remote Desktop enabled might experience Remote Desktop Services (RDS) instability. | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved KB5129194 | 2026-09-14 10:00 PT |
| Host folder shares might be unavailable in Hyper-V-based Linux VMs Plan9 host folder shares might not appear in the guest environment after installing the September 2026 security update. | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved KB5129194 | 2026-09-14 10:00 PT |
| Microsoft Teams and Outlook might fail to launch on ARM-based devices This most likely occurs on new PCs after installing the August Windows security update and does not affect other apps. | OS Build 28000.2704 KB5121000 2026-08-11 | Resolved KB5124012 | 2026-09-08 10:00 PT |
| Windows Server Update Services sync operations might have issues or time out Remediation efforts are underway. Synchronization times are expected to return to normal as recovery progresses. | N/A | Resolved | 2026-07-20 13:22 PT |
| GIF functionality in the Windows Emoji Panel might become unavailable This issue occurs because the previous GIF provider (Tenor) retired its service on June 30, 2026. | N/A | Resolved KB5095091 | 2026-06-23 10:00 PT |
| Deleting a file from the Recycle Bin displays an internal filename in the dialog This issue only occurs within the confirmation dialog after installing the June Windows security update. | OS Build 28000.2269 KB5095051 2026-06-09 | Resolved KB5095091 | 2026-06-23 10:00 PT |
Issue details
October 2026
Devices might experience a black screen or desktop loading issues after sign-in
| Status | Originating update | History |
|---|---|---|
| Resolved KB5127646 | OS Build 28000.2804 KB5120996 2026-08-27 | Resolved: 2026-10-13, 10:00 PT Opened: 2026-10-13, 09:49 PT |
After installing the August 2026 Windows non-security preview update (KB5120996) and subsequent updates, some devices might experience desktop loading issues. This issue has been primarily observed on Azure Virtual Desktop (AVD) hosts, using FSLogix. This issue appears to occur more frequently with some existing user profiles.
Symptoms might include:
- A black screen appears after sign-in and the desktop session does not load automatically.
- Users might be unable to access their desktop until the desktop session is started manually.
- Application event logs might show Windows Explorer crashes.
Resolution: This issue was resolved by Windows updates released October 13, 2026 (KB5127646), and updates released after that date. We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one.
If you install an update released October 13, 2026 (KB5127646), or later, you do not need to use a workaround for this issue. If you are using an update released before October 13, and have this issue, you have the option to apply the following workaround.
Workaround: Affected customers can apply one of the following workarounds to mitigate the issue:
- Manually launch explorer.exe: Users can temporarily mitigate this issue by opening Task Manager (Ctrl+Shift+Esc), selecting Run new task, entering explorer.exe, and selecting OK.
- Mitigate through Known Issue Rollback (KIR): This issue is mitigated using Known Issue Rollback (KIR).
For enterprise-managed devices where Windows updates are managed by IT departments, IT administrators can apply the KIR by installing and configuring the Group policy listed below. The special Group Policy can be found in Computer Configuration > Administrative Templates > <Group Policy name listed below>
Group Policy downloads with Group Policy name:
- Download for Windows 11, version 26H1: KB5124006 260924_20071 Known Issue Rollback
- Download for Windows 11, version 26H2, Windows 11, version 25H2 and Windows 11, version 24H2: KB5124010 260924_20021 Known Issue Rollback
Important: You will need to install and configure the Group Policy for your version of Windows to resolve this issue. You will also need to restart your device(s) to apply the group policy setting. Note that this Group Policy will disable the change causing this issue until a resolution is released in a future Windows update.
For information on deploying and configuring this special Group Policy, please see How to use Group Policy to deploy a Known Issue Rollback
Affected platforms:
- Client: Windows 11, version 26H2; Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2
- Server: None
September 2026
Domain-joined devices might lose their secure trust relationship with the domain
| Status | Originating update | History |
|---|---|---|
| Resolved KB5124006 | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved: 2026-09-22, 10:00 PT Opened: 2026-09-16, 14:15 PT |
After installing the September 8, 2026, Windows security update (KB5124012), or the September 14, 2026, Windows out-of-band update (KB5129194), some Credential Guard protected machine accounts might lose their secure channel with an on-premises Active Directory (AD) domain. 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 these updates enable the Machine Identity Isolation feature. While the updates do 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.
Resolution: This issue was resolved by Windows updates released September 22, 2026 (KB5124006), and updates released after that date. This update prevents Machine Identity Isolation (MII) enforcement by disabling it completely while improvements are made to the feature. MII enforcement will be prevented regardless of the MII configuration.
If you install an update released September 22, 2026 (KB5124006) or later, you do not need to use a workaround for this issue. If you are using an update released before September 22, 2026, and have this issue, you have the option to apply one of the following workarounds.
Workaround #1: Known Issue Rollback
IT administrators can resolve the issue using Known Issue Rollback (KIR) by installing and configuring the special Group Policy listed below.
Group Policy downloads with Group Policy name:
- Download for Windows 11, version 26H1 — KB5124012 260915_17122 Known Issue Rollback
The special Group Policy can be found in Computer Configuration > Administrative Templates > KB5124012 260915_17122 Known Issue Rollback > Windows 11, version 26H1. After installing the Group Policy, configure the value for setting KB5124012 260915_17122 Known Issue Rollback to Disabled and restart your device(s) to apply the Group Policy setting. For information on deploying and configuring the special Group Policy, please see How to use Group Policy to deploy a Known Issue Rollback.
Workaround #2: Disable Machine Identity Isolation manually
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 26H2 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 for MachineIdentityIsolation = 2, then set 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)'
Affected platforms:
- Client: Windows 11, version 26H2; Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2
- Server: None
Remote Desktop Services might stop responding after Sept. 2026 security update
| Status | Originating update | History |
|---|---|---|
| Resolved KB5129194 | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved: 2026-09-14, 10:00 PT Opened: 2026-09-11, 11:19 PT |
After installing the September 2026 Windows security update (KB5124012), 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 (KB5129194), 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
| Status | Originating update | History |
|---|---|---|
| Resolved KB5129194 | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved: 2026-09-14, 10:00 PT Opened: 2026-09-11, 02:22 PT |
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 KB5124012, 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 (KB5129194), 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
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Microsoft Teams and Outlook might fail to launch on ARM-based devices
| Status | Originating update | History |
|---|---|---|
| Resolved KB5124012 | OS Build 28000.2704 KB5121000 2026-08-11 | Resolved: 2026-09-08, 10:00 PT Opened: 2026-09-01, 18:46 PT |
After installing Windows security updates released on or after August 11, 2026, (KB5121000), Microsoft Teams and the new Outlook for Windows might fail to launch or might close unexpectedly on ARM-based devices, such as Surface Pro 11 and Surface Laptop 7. Classic Outlook, Word, Excel, and other applications are not known to be affected. This issue is most likely to occur on new or freshly imaged PCs that have not yet installed any Microsoft Store updates.
Resolution: This issue was resolved by Windows updates released September 8, 2026 (KB5124012), and updates released after that date. We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one.
If you install an update released September 8, 2026 (KB5124012), or later, you do not need to use a workaround for this issue. If you are using an update released before September 8 and have this issue, you have the option to apply the following workaround.
Workaround: To work around this issue:
- Open Microsoft Store.
- Select Downloads > Check for updates.
- Install the latest update for the Auto Super Resolution Package (version 1.0.19.0 or later).
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2
- Server: None
August 2026
Incorrect notifications that "Microsoft Defender Antivirus is turned off"
| Status | Originating update | History |
|---|---|---|
| Resolved | N/A | Resolved: 2026-09-30, 16:42 PT Opened: 2026-08-28, 15:34 PT |
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
July 2026
Windows Server Update Services sync operations might have issues or time out
| Status | Originating update | History |
|---|---|---|
| Resolved | N/A | Resolved: 2026-07-20, 13:22 PT Opened: 2026-07-17, 18:18 PT |
Microsoft has identified a service degradation affecting Windows Server Update Services (WSUS). Organizations might experience increased synchronization times or sync operation timeouts on WSUS servers. This issue began in recent days, with heightened impact observed starting July 13, 2026, and service-side mitigation on Saturday July 18, 2026. After this day, synchronization times and sync operations are expected to be restored to normal.
This issue is related to a buildup of publishing metadata which is present on existing WSUS server installations as well as from the service side.
Resolution: There are two parts to the resolution of this issue.
- Organizations with existing WSUS server installations that are experiencing long sync times can benefit from manual steps in order to clean up unneeded metadata. This metadata is present in existing WSUS installations but can be safely removed. Detailed guidance has been provided at the following KB article: https://support.microsoft.com/help/5121986.
- On July 18, 2026, Microsoft deployed a service-side mitigation which returns synchronization times and sync operations back to normal for new WSUS installations and rebuilds. After this date, newly installed or rebuilt WSUS servers should not encounter this issue.
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, version 1809; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016; Windows 10, version 1607
- Server: Windows Server 2025; Windows Server 2022; Windows Server, version 1809; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012
June 2026
GIF functionality in the Windows Emoji Panel might become unavailable
| Status | Originating update | History |
|---|---|---|
| Resolved KB5095091 | N/A | Resolved: 2026-06-23, 10:00 PT Opened: 2026-06-30, 10:23 PT |
Starting on June 30, 2026, you might not see GIF options in the Windows Emoji Panel on some devices and instead see a message stating “GIF service is not available.” This issue occurs because the previous GIF provider (Tenor) retired its service on that date.
Resolution: This issue was resolved by Windows updates released June 23, 2026 (KB5095091), and later. These updates include a new GIF provider (GIPHY). To restore GIF functionality in the Windows Emoji Panel, install the latest available Windows updates, which contains important improvements and issue resolutions, including this one.
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2
- Server: none
Deleting a file from the Recycle Bin displays an internal filename in the dialog
| Status | Originating update | History |
|---|---|---|
| Resolved KB5095091 | OS Build 28000.2269 KB5095051 2026-06-09 | Resolved: 2026-06-23, 10:00 PT Opened: 2026-06-18, 12:03 PT |
When permanently deleting a single item from the Recycle Bin, the confirmation dialog displays the internal Recycle Bin filename (for example, $Rxxxxx.ext) instead of the original filename. The Recycle Bin itself correctly displays the original filename, and restoring the item also restores it using the original filename.
This issue occurs after installing the Windows security update released on June 9, 2026 (KB5095051).
Resolution: This issue was resolved by Windows updates released June 23, 2026 (KB5095091), and later. We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one. If your organization has installed an update released on June 23, 2026, or later, you do not need to use a Known Issue Rollback (KIR) or a special Group Policy to resolve this issue.
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 Enterprise LTSC 2021; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSB 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
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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.
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