Windows bugs and fixes September 26 2026: black screen
Chapters
What broke on Windows 11?
Windows Explorer can fail after sign-in on Windows 11, Cyberpress reported on September 26, 2026.
Cyberpress reported on September 26, 2026, that affected sessions can show a black screen instead of the taskbar, Start menu, desktop icons and normal shell functions because the desktop session does not start automatically. Application event logs can record Windows Explorer crashes, even though authentication has completed and the user session is running.
BleepingComputer reported on September 25, 2026, that the Windows 11 bug mainly affects Azure Virtual Desktop hosts using FSLogix and can appear after the August 2026 preview updates or subsequent updates. Certain existing user profiles are affected more frequently, according to Cyberpress on September 26, 2026.
Cyberpress reported on September 26, 2026, that KB5120996 is the originating August 2026 non-security preview update for Windows 11 version 26H1. The same report names KB5120998 as the originating update for Windows 11 versions 25H2 and 24H2. BleepingComputer reported on September 25, 2026, that later affected updates include KB5124008 and KB5122880. Microsoft classified the incident as mitigated, Cyberpress reported on September 26, 2026, but mitigation is not the same as a permanent Windows update fix. My position is that Microsoft publishes Windows known issues, their workarounds and their fix builds on release health and in KB articles, so a Windows problem that looks mysterious on a help desk queue is usually already documented, dated and attributable.
TL;DR
For Windows bugs and fixes September 26 2026, Cyberpress reported on September 26, 2026, that Windows Explorer can fail after sign-in on Windows 11, leaving a black screen. Microsoft has mitigated the issue, but no permanent code fix has shipped; Tech Insider reported on September 24, 2026, that the separate File History failure is fixed in updates including KB5124010.
- Cyberpress reported on September 26, 2026, that KB5120996 started the black-screen issue on Windows 11 version 26H1.
- Cyberpress reported on September 26, 2026, that KB5120998 is the originating update for Windows 11 versions 25H2 and 24H2.
- Microsoft provides a manual
explorer.exeworkaround and Known Issue Rollback policies, according to BleepingComputer on September 25, 2026. - Tech Insider reported on September 24, 2026, that updates released on and after September 22, 2026, resolve the File History failure.
Has a permanent black-screen fix shipped?
No permanent correction has shipped, Cybersecuritynews reported on September 25, 2026.
Cybersecuritynews reported on September 25, 2026, that Microsoft continues developing a permanent correction for a future Windows update. The immediate workaround is to open Task Manager, select Run new task, enter explorer.exe, and select OK. That command starts the Windows shell and can restore the desktop for the current session, but it does not remove the underlying regression.
For enterprise-managed Windows 11 version 26H1 devices, Cybersecuritynews reported on September 25, 2026, that administrators should deploy the KB5124006 260924_20071 rollback policy. Windows 11 versions 25H2 and 24H2 require KB5124010 260924_20021. Administrators must install the matching policy, configure it under Computer Configuration > Administrative Templates, and restart every affected device.
Cybersecuritynews reported on September 25, 2026, that the Known Issue Rollback reverses only the problematic non-security change while preserving the rest of the installed update. Managed devices ordinarily refresh policy within 90 to 120 minutes, while gpupdate can accelerate retrieval, but every endpoint still requires a restart. The tradeoff is clear. Manually starting Explorer restores only the affected session, while the managed rollback requires administrator work and a restart. My position is that a user facing a black screen should apply Microsoft's documented shell workaround immediately rather than wait for scheduled IT maintenance.
Which Windows fixes have already shipped?
File History is fixed in KB5124010, Tech Insider reported on September 24, 2026.
Tech Insider reported on September 24, 2026, that Microsoft's support documentation was updated on September 22, 2026, and says the File History problem is resolved in updates released on and after that date. The failure began after the September 2026 security update KB5124008 and could prevent customers from creating or updating backups.
I covered the earlier failure in my Windows bugs and fixes report for September 24, 2026. The useful change now is status: the File History problem has a shipped fix, while the Explorer black-screen problem has only a workaround and rollback mitigation.
KB5124010 also has a separate warning. The FPS Review reported on September 25, 2026, that Battlefield 6 can crash to the desktop about 20 seconds after launch following installation of the optional update. The report says the game developer tied the WD-L020 launch error to KB5124010 and was still investigating a fix. The FPS Review reported on September 25, 2026, that uninstalling KB5124010 and restarting restored affected games for some players, but the removal is optional and at the user's own risk. Battlefield 6 and Wardogs use kernel-level anti-cheat, yet the report says nobody has confirmed the failure mechanism. I would treat that connection as an active investigation, not a Microsoft-confirmed cause.
What can a Windows user do today?
Run explorer.exe manually for an affected session, BleepingComputer advised on September 25, 2026.
Press Ctrl+Shift+Esc, select Run new task, enter explorer.exe, and select OK, according to BleepingComputer on September 25, 2026. The desktop should return for that session, but BleepingComputer says a permanent fix remains unavailable. Save open work after access returns because the workaround does not correct the installed change.
On a managed computer, give the administrator the Windows 11 version and originating update. Cybersecuritynews reported on September 25, 2026, that version 26H1 needs KB5124006 260924_20071, while versions 25H2 and 24H2 need KB5124010 260924_20021. The administrator must configure the policy and restart the device.
For File History, install an update released on or after September 22, 2026, including KB5124010, as Tech Insider reported on September 24, 2026. Then create or update a backup rather than assuming the feature resumed silently. A working backup is the result that matters. For repeated Battlefield 6 crashes after installing the optional KB5124010 update, The FPS Review advised on September 25, 2026, that affected users can remove the update, restart, and avoid selecting Download and install. The removal is optional and at the user's own risk, and the developer's investigation has not established the mechanism. I would not remove updates merely because a Windows KB update problem exists elsewhere. Match the symptom, Windows version and KB first. Microsoft's published status distinguishes a shipped File History fix from a mitigated Explorer failure, which is enough information for ordinary users and IT firms to act today.