Microsoft: Windows updates cause black screen at sign-in

Microsoft confirmed that August 2026 preview updates and later patches cause desktop loading issues, including black screens and Explorer crashes, mainly on Azure Virtual Desktop hosts using FSLogix. A temporary workaround is to manually launch explorer.exe via Task Manager.

• Affected updates: KB5120996, KB5120998, KB5124008, KB5122880
• Symptoms: black screen after sign-in and Windows Explorer crashes
• Workaround: launch explorer.exe via Task Manager
• Enterprises can apply Known Issue Rollback group policies