Windows KB5013943 Update Is Causing Blue Screen of Death Via Sophos Antivirus


Cybersecurity vendor Sophos has released a fix for an error triggering Blue Screens of Death. The cases were reported on Windows 11 by users running Sophos Home antivirus after installing the KB5013943 update. The update rolled out critical security fixes for vulnerabilities detected in the recent past in the May 2022 patch.

The company says, “Customers running Sophos Home Antivirus on Windows 11 may encounter a stop error/BSOD after installing KB5013943 update.”

The users are unable to get to the desktop after restarting/power on attempts in post-installation of the said update. Apart from the BSOD error, this update is also causing the ‘application unable to start correctly ‘ error when users start .NET applications.

Though other affected apps may vary per user, the commonly reported ones are Proton VPN, Visual Studio, Discord, and ShareX among others.

Blue Screen of Death error on Windows 10

The BSOD cause and fix

According to Sophos, this BSOD originates from the ‘HitManPro.AlertSupport’ Windows driver which is used by Sophos Antivirus. The fix for this known bug has been released and will automatically apply to all affected systems as soon as the patch is applied.

To check whether the issue has been fixed, users can navigate to C:\Windows\System32\drivers and check ‘hmpalert.sys’ details. The product version should be

Alternatively, users who have not received the automatic fix can rename the hmpalert.sys driver. Additionally, users can also uninstall the KB5013943 update. The latter is not recommended and should only be used as a last resort.

To remove this update, users should let the system crash to BSOD three times and then ‘click advanced repair options.

To complete the process one should navigate to Troubleshoot > Advanced options > Uninstall updates > Uninstall latest quality update.

Regardless of any workaround used, Sophos is asking users to verify if the fix has been applied.

Other causes of Blue Screen of Death error

Apart from Sophos Antivirus, BSOD can also be caused by poorly written device drivers. Hardware malfunctioning such as overheating of components or power supply issues could also lead to BSOD error.

Incompatible dynamic link libraries(DLLs) or bugs in the operating system kernel could also lead to the same.