Microsoft has officially acknowledged a significant disruption affecting Windows 11 version 24H2 users, specifically after installing the cumulative update KB5062553 released in July 2025.
The issue primarily affects environments using Virtual Desktop Infrastructure (VDI) and devices undergoing their first user logon.
Reports indicate that essential shell components, including the Start Menu, Taskbar, and System Settings, are failing to initialize correctly, leaving users with a severely degraded or unusable desktop experience.
The disruption stems from the operating system’s inability to register specific dependency packages in time during the logon process. This behavior is particularly acute in non-persistent OS installations where application packages must be provisioned fresh for each user session.
Administrators managing virtual environments have reported that users are frequently greeted with empty taskbars, unresponsive Start buttons, or immediate crashes of the explorer.exe process upon signing in.
The problem is not limited to VDI; standard physical workstations can also exhibit these symptoms during the initial user profile creation immediately following the update application.
The root cause has been identified as a race condition involving XAML (Extensible Application Markup Language) components. These components are critical for rendering the modern Windows UI.
When the update is applied, the dependent packages required by the shell do not register before the shell attempts to load them. This results in silent failures or explicit error messages from processes such as StartMenuExperienceHost.exe and ShellHost.exe.
The following table details the specific components and packages involved in this failure:
| Component | Reported Symptom | Affected XAML Dependency |
|---|---|---|
| Explorer.exe | Runs without a visible taskbar window or crashes repeatedly | MicrosoftWindows.Client.CBS_cw5n1h2txyewy |
| Start Menu | Fails to launch; displays critical error message | Microsoft.UI.Xaml.CBS_8wekyb3d8bbwe |
| System Settings | Silently fails to launch when accessing Start > Settings > System | MicrosoftWindows.Client.Core_cw5n1h2txyewy |
| ImmersiveShell | Fails to initialize, causing black screen or limited UI | All XAML island views |
Workaround and Mitigation Strategies
Microsoft is actively developing a permanent resolution for this regression. In the interim, IT administrators and affected users can restore functionality by manually registering the missing packages. For persistent installs, these commands must be run within the user session, followed by a restart of the SiHost process.
Manual Registration Commands:
powershellAdd-AppxPackage -Register -Path 'C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\appxmanifest.xml' -DisableDevelopmentMode
Add-AppxPackage -Register -Path 'C:\Windows\SystemApps\Microsoft.UI.Xaml.CBS_8wekyb3d8bbwe\appxmanifest.xml' -DisableDevelopmentMode
Add-AppxPackage -Register -Path 'C:\Windows\SystemApps\MicrosoftWindows.Client.Core_cw5n1h2txyewy\appxmanifest.xml' -DisableDevelopmentMode
For VDI and non-persistent environments where this issue recurs at every logon, a synchronous logon script is the recommended solution. This script ensures that explorer.exe is blocked from launching until the necessary XAML packages are fully provisioned, preventing the race condition.
VDI Logon Script Wrapper:
text@echo off
REM Register MicrosoftWindows.Client.CBS
powershell.exe -ExecutionPolicy Bypass -Command "Add-AppxPackage -Register -Path 'C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\appxmanifest.xml' -DisableDevelopmentMode"
REM Register Microsoft.UI.Xaml.CBS
powershell.exe -ExecutionPolicy Bypass -Command "Add-AppxPackage -Register -Path 'C:\Windows\SystemApps\Microsoft.UI.Xaml.CBS_8wekyb3d8bbwe\appxmanifest.xml' -DisableDevelopmentMode"
REM Register MicrosoftWindows.Client.Core
powershell.exe -ExecutionPolicy Bypass -Command "Add-AppxPackage -Register -Path 'C:\Windows\SystemApps\MicrosoftWindows.Client.Core_cw5n1h2txyewy\appxmanifest.xml' -DisableDevelopmentMode"
Administrators are advised to test these scripts in a staging environment before broad deployment to production VDI pools.
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