Microsoft Fixes Windows 11 Update Issue that Causes Black Screen Errors or Windows Explorer crash
Microsoft fixed a Windows 11 update bug causing black screens and Explorer crashes, mainly on AVD with FSLogix.
Microsoft marked a Windows 11 sign-in failure as resolved on October 13, 2026. After the August non-security preview KB5120996, some users, mainly Azure Virtual Desktop hosts using FSLogix, saw a black screen or Windows Explorer crashes and had to start the desktop manually. Affected client versions include 26H2, 26H1, 25H2, and 24H2; Windows Server is not affected. The fix is in KB5127646 for version 26H1, reaching Build 28000.3231, and later updates. Microsoft says the notice does not identify malware or an attack.
- Black screens and Explorer crashes followed the August 2026 preview update.
- Impact was mainly Azure Virtual Desktop hosts using FSLogix.
- KB5127646, released October 13, fixes Windows 11 26H1.
- Microsoft says the issue is not malware or an attack.
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Microsoft fixed a Windows 11 update issue that could leave users staring at a black screen after signing in or cause Windows Explorer to crash.
The problem mainly affected Azure Virtual Desktop hosts using FSLogix, and some existing user profiles were more likely to fail to load the desktop. Microsoft marked the issue as resolved on October 13, 2026.
The fix is included in KB5127646 for Windows 11 version 26H1 and later updates. Microsoft recommends installing the latest available update on each device. Systems running the October 13 update or later no longer need the temporary workarounds for this issue.
According to Microsoft’s Windows release health notice, the problem began after the August 2026 non-security preview update, KB5120996. It continued through subsequent updates for Windows 11 version 26H1; that originating update carried OS Build 28000.2804.
Affected users could sign in but found their desktop session did not load automatically. Instead, a black screen appeared, leaving them unable to access the desktop until they started the session manually. Application event logs could also show Windows Explorer crashes, giving administrators a useful sign when checking affected systems.
Microsoft Fixes Windows 11 Update Issue
Microsoft lists Windows 11 versions 26H2, 26H1, 25H2, and 24H2 as affected client platforms. This issue does not affect Windows Server. Although reports mainly involved Azure Virtual Desktop environments using FSLogix, Microsoft did not describe every device running those Windows versions as affected.
Cybersecurity News previously covered the Windows 11 update bug causing black screens, including the temporary recovery steps available before this fix. The new resolution removes the need to rely on those measures once an affected device receives the appropriate update.
Users still running an update released before October 13 can temporarily restore desktop access by pressing Ctrl+Shift+Esc to open Task Manager. They can then select Run new task, enter explorer.exe, and choose OK. Microsoft provides this method as a workaround, not a replacement for installing the fix.
For enterprise-managed devices, administrators can also use Known Issue Rollback, or KIR, through a special Group Policy. The supplied notice identifies KB5124006 260924_20071 for Windows 11 26H1 and KB5124010 260924_20021 for Windows 11 26H2, 25H2, and 24H2.
Administrators must install and configure the policy that matches their Windows version, then restart affected devices. This turns off the change responsible for the issue.
Cybersecurity News also reported on another Windows 11 update fix that replaced a temporary rollback, showing why a workaround and a permanent update aren’t the same.
First, match the symptoms to Microsoft’s health notice and confirm the installed Windows version and update level. Reported signs include a black screen after sign-in, failure to load the desktop, and Windows Explorer crashes. The notice does not identify malware or an attack as the cause.
Microsoft’s Windows 11 release information lists KB5127646 as the October 13 security update for version 26H1, bringing it to Build 28000.3231. Administrators should use the update appropriate for each supported Windows release rather than assume the same package applies across every affected version
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Abinayahttps://cybersecuritynews.com/
Abi is a Security Editor and fellow reporter with Cyber Security News. She is covering various cyber security incidents happening in the Cyber Space.