Microsoft: Windows 11 updates can black-screen Azure Virtual Desktop

Microsoft says August 2026 Windows 11 updates can leave FSLogix-based Azure Virtual Desktop sessions on a black screen after sign-in.

Microsoft confirmed that Windows 11 updates beginning with the August 2026 non-security preview can stop the desktop shell from loading after sign-in, causing a black screen and Windows Explorer crashes. Cyber Security News dates the start to August 27, 2026, while BleepingComputer describes August 2026 preview updates and later releases more broadly and GBHackers says later cumulative updates may also be involved. The problem mainly affects Azure Virtual Desktop hosts that use FSLogix; only Cyber Security News specifies certain existing profiles. Cyber Security News and GBHackers link 26H1 to KB5120996 (OS Build 28000.2804) and 24H2/25H2 to KB5120998, but BleepingComputer also lists KB5124008 and KB5122880, which the others do not. Until a permanent fix, users can launch explorer.exe—GBHackers says this restores the shell but does not fix the bug—and enterprises can apply Known Issue Rollback policies KB5124006 and KB5124010 and reboot. Microsoft calls the issue mitigated; only Cyber Security News states that Windows Server is not listed as affected, and GBHackers adds that Application logs may show Explorer.exe crashes.

• Microsoft confirmed that Windows 11 updates starting with the August 2026 non-security preview can leave a black screen after sign-in when Explorer fails to start.
• Cyber Security News dates the start to August 27, 2026; BleepingComputer says August 2026 preview updates and later releases, and GBHackers says possibly later cumulative updates as well.
• The issue mainly affects Azure Virtual Desktop hosts using FSLogix; only Cyber Security News specifies certain existing profiles.
• 26H1 is tied to KB5120996 (OS Build 28000.2804) and 24H2/25H2 to KB5120998; only BleepingComputer also lists KB5124008 and KB5122880.
• Users can launch explorer.exe from Task Manager; GBHackers says this restores the shell but does not fix the bug.
• Enterprises can deploy Known Issue Rollback policies KB5124006 and KB5124010 and reboot; a permanent fix has not been released.
• Microsoft calls the issue mitigated; only Cyber Security News says Windows Server is not listed as affected.
• GBHackers says Application logs may show Explorer.exe crashes.