Microsoft fixes bug causing Windows black screens, Explorer crashes

A bug in Windows 11 updates released since August 2026 caused black screens after sign-in, inability to access the desktop until manually starting the desktop session, and Windows Explorer crashes, mainly impacting Azure Virtual Desktop hosts using FSLogix. Microsoft addressed this issue in cumulative updates released on October 13, 2026, and later. For those unable to update immediately, a manual workaround to launch Explorer.exe is available. Enterprise environments can deploy Known Issue Rollback group policies (KB5124006 for version 26H1 and KB5124010 for versions 25H2 and 24H2) to disable the problematic change until the fix is applied.

Affected users experienced black screens after sign-in, desktop loading failures, and Windows Explorer crashes, disrupting normal desktop access and usability. The issue mainly impacted Azure Virtual Desktop hosts using FSLogix, affecting virtual desktop environments. There is no indication of security compromise or data loss associated with this bug.

Microsoft has released official cumulative updates on October 13, 2026, and later that fully resolve this issue. Users are strongly advised to install the latest Windows updates to receive the fix. For those who cannot update immediately, manually launching Windows Explorer via Task Manager (Ctrl+Shift+Esc, Run new task, enter explorer.exe) serves as a temporary workaround. Enterprise customers can apply Known Issue Rollback group policies (KB5124006 for Windows 11 version 26H1 and KB5124010 for versions 25H2 and 24H2) to mitigate the issue until updates are deployed. A system restart is required after applying these policies.