Windows 11 Update KB5013943 drops BSODs and causes issues with Sophos driver

Windows[German]Another May 2022 patchday issue on Windows 11. Users who have been running Sophos antivirus solutions may have been seeing BlueScreens on Windows 11. The cause is the May 10, 2022 update KB5013943, which causes problems with a Sophos driver. Sophos has meanwhile released a fix to resolve this issue.


Windows 11 Update KB5013943

Cumulative update KB5013943 raises the OS build on Windows 11 to 22000.675 (see also Patchday: Windows 11/Server 2022-Updates (May 10, 2022)). According to Microsoft, the update is intended to fix an issue caused by preview update KB5012643, which can cause the screen to flicker when you boot a device in Safe Mode (see Windows 11: Preview update KB5012643 causes display issues in safe mode). However, the update is responsible for numerous issues in Windows 11 (see Windows, Office: May 2022 Patchday issues and mysteries).

Update triggers BlueScreens with Sophos driver

After installing the cumulative update KB50139433, Windows 11 users running a Sophos antivirus solution like Sophos Home (and also Sophos Intercept X) observe a blue screen. HardForum already had this warning on Saturday, May 14, 2022.

Windows 11 and Windows Update KB5013943 warning with Sophos

I have actually already delt with this and got working again. But this morning the malware/ virus software I run (Sophos Home) posted a warning as I booted up letting customers know this is an issue and not to install the update.

Windows 11 Bluescreen/stop error after Windows Update KB5013943​

Customers on Windows 11 running Sophos Home may encounter a BSOD/Stop error after installing Windows Update KB5013943 and restarting their machines.

The symptoms involve being unable to get to the desktop after restarting the computer/shutting down powering it back on post installation of Windows Update KB5013943. This includes a Stop Error Index Mismatch message (Blue Screen)

Also on there is this post in the May 2022 patchday megathread addressing problems with Sophos Home. However, there were probably no problems with Sophos Intercept X, as the user write within the thread. Addendum: Got a report on Facebook, that also Sophos Intercept X is affected.

Sophos has fixed the issue

Sophos already published the support post FIXED- Windows 11 Bluescreen/stop error after Windows Update KB5013943 on May 14 or 15, 2022, but updated it on 5/17/2022. There it is confirmed that Windows 11 users with Sophos Home, run into problems after installing the May 10, 2022 update KB5013943. After installation and reboot, the following problems may occur:

  • The system crashes with a BlueScreen "Stop Error Index Mismatch"
  • The desktop can no longer be accessed (after a Windows (re)start)

The cause is probably an incompatible Sophos driver hmpalert.sys in the Windows subfolder System32\drivers. Sophos has released an update for Sophos Home on May 15, 2022, which upgrades the hmpalert.sys driver to version This version should fix the problems. The support article describes how to check the driver version. (via)


Similar articles:
Microsoft Office Updates (May 3, 2022)
Microsoft Security Update Summary (May 10, 2022)
Patchday: Windows 10-Updates (May 10, 2022)
Patchday: Windows 11/Server 2022-Updates (May 10, 2022)
Windows 7/Server 2008R2; Windows 8.1/Server 2012R2: Updates (May 10, 2022)
Exchange Server Security Updates (May 10, 2022)

Windows 11: Update KB5013943 results in application error 0xc0000135
MS-Patchday wrap-up: Issues with April 2022 updates
Windows Server 2022: RDS bug (RDCB role broken) caused by KB5011497, not fixed in May 2022
Windows Update KB5012599: Microsoft plans fix for install error 0x8024200B and 0x800F0831
Windows 11: Update KB5013943 results in application error 0xc0000135


Exchange Server Sicherheitsupdates (10. Mai 2022)

Patchday-Nachlese: Probleme mit April 2022-Updates
Windows, Office: Mai 2022 Patchday-Probleme und Besonderheiten
Windows 11: Update KB5013943 erzeugt Fehler 0xc0000135
Windows 11 Update KB5013943 verursacht Probleme mit DATEV (0xc0000135)
Windows Server 2022: März 2022-Update KB5011497 verursacht Probleme mit Remote-Desktop-Rollen/-Verbindungen
Windows Server 2022: Lösung für Remote Desktop-Probleme mit Update KB5011497
Windows Server 2022: Wie ist der Status beim RDS-Bug (RDCB-Rolle), verursacht durch KB5011497?
Windows Update KB5012599: Fix für Installationsfehler 0x8024200B und 0x800F0831 kommt

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