Windows 11 26H2: Black screen or desktop does not load after sign-in (fixed in KB5127648)
Summary
After installing Windows 11, version 26H2 and subsequent updates, some devices may fail to load the desktop after sign-in. The issue was mainly observed on Azure Virtual Desktop (AVD) hosts using FSLogix, more often with some existing user profiles. Microsoft resolved it with the updates released on 2026-10-13 (KB5127648) and later.
Symptoms
- A black screen appears after sign-in and the desktop session does not load automatically.
- Users cannot access their desktop until the session is started manually.
- Application event logs may show Windows Explorer crashes.
Affected
- Windows 11, version 26H2
- Windows 11, version 26H1 (originating update KB5120996, OS build 28000.2804; fixed by KB5127646)
- Windows 11, version 25H2 (originating update KB5120998, OS build 26200.9278)
- Windows 11, version 24H2 (originating update KB5120998, OS build 26100.9278)
- Mainly AVD hosts with FSLogix
- Windows Server: not affected
Workaround
Only needed on updates released before 2026-10-13:
- Temporary: open Task Manager (Ctrl+Shift+Esc), select Run new task, enter explorer.exe and select OK.
- Known Issue Rollback (KIR): install and configure the Group Policy KB5124010 260924_20021 Known Issue Rollback (26H2, 25H2, 24H2) or KB5124006 260924_20071 Known Issue Rollback (26H1). Find it under Computer Configuration > Administrative Templates, then restart the devices. The policy disables the change causing the issue until a fix is installed.
Fix
Resolved by the Windows updates released on 2026-10-13 (KB5127648 for 26H2, 25H2 and 24H2; KB5127646 for 26H1) and later updates. No workaround is needed with these updates.
Recommendation
Install the latest Windows update (at least KB5127648) on all affected Windows 11 devices, especially AVD hosts with FSLogix. Use the KIR only if you cannot update yet, and remove it once the fix is installed.
Reports from the community and trade media
Reports from forums, Q&A sites, Reddit and trade media – linked only, without the names of the authors; the vendor’s statement is authoritative.
- Microsoft: recent Windows updates cause desktop loading issues News · bleepingcomputer.com, 25 Sep 2026
- Windows 11 26H2 release health status Vendor · learn.microsoft.com, 28 Oct 2026
- Microsoft fixes bug causing Windows black screens, Explorer crashes News · bleepingcomputer.com, 14 Oct 2026
- Microsoft warns of desktop loading issues and black screens News · betanews.com, 27 Sep 2026
- Windows 11 26H1 release health Vendor · learn.microsoft.com, 13 Oct 2026
Sources
- Windows release health: Windows 11, Version 26H2 Vendor · learn.microsoft.com
- KB5127648 Vendor · support.microsoft.com
- Windows release health: Windows 11, Version 26H1 Vendor · learn.microsoft.com
- KB5127646 Vendor · support.microsoft.com
- How to use Group Policy to deploy a Known Issue Rollback Vendor · learn.microsoft.com
- What is FSLogix Vendor · learn.microsoft.com
Compiled from the sources listed and translated with AI (Claude); status and dates come from the vendor. The vendor’s statements are authoritative. Updated 1 Nov 2026, 15:47.
Where the information comes from
We continuously read the vendors’ official sources, community reports and trade media and summarise them in our own words, with a link to the source:
- Microsoft: Windows release health (Windows 10/11, Server 2016 to 2025), Windows message center, known issues of Microsoft 365 Apps (Outlook, Excel, Word, PowerPoint), Edge, Intune, Autopilot, Windows 365 and Entra Connect, Microsoft KB articles with timelines, Exchange and Windows IT Pro blogs, optionally Microsoft 365 service health and message center
- other vendors: Veeam KB, Citrix (known issues), Ubuntu and Debian (regressions), Broadcom (VMware), Fortinet, Cisco, Mozilla, Let’s Encrypt
- community (title, short excerpt and link only, without the names of the authors): Microsoft Q&A, Microsoft Tech Community (discussions), Veeam R&D Forums, Eleven Forum
- targeted web research with AI (Claude), e.g. on the updates of the month – this also finds discussions on Reddit and in forums; such entries are labelled as community reports until the vendor confirms them
- early warning from trade media (title and link only): Born’s Tech and Windows World, BleepingComputer, AskWoody, Windows Latest, Windows Central, gHacks, The Windows Club, Deskmodder, Dr. Windows, WindowsArea, Frankys Web, heise online
Summary and translation with AI (Claude by Anthropic) – without any data of visitors.
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