KB5094126 security update didn't fix the virtualization blue screens for me.

Francis Alužāns 20 Reputation points
2026-06-12T16:54:15.3466667+00:00

For quite some time I was on version KB5089549 and I, roughly 75% of the time was getting the HYPERVISOR_ERROR and KMODE_EXCEPTION_NOT_HANDLED blue screens when launching the game Valorant with a kernel level anti-cheat called Vanguard. I was excited to see that KB5094126 "fixed" these errors, but after updating and trying out the game I was still met with the HYPERVISOR_ERROR blue screens. Could there be a fix for these errors or a way to find what is causing them?

Windows for home | Windows 11 | Windows update
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David-M 126.8K Reputation points Independent Advisor
2026-06-12T18:34:51.6366667+00:00

Thanks.

Based on the minidumps you provided, each individual crash points to a different cause, specifically referencing the Vanguard driver (vgk.sys), the Nvidia driver, and the Windows Cryptography Next Generation driver (cng.sys) across separate logs.

According to the release notes for update KB5094126, the specific virtualization fix was designed to address a regression introduced in the previous preview update (KB5089573). Since you were already experiencing these HYPERVISOR_ERROR and KMODE_EXCEPTION_NOT_HANDLED crashes on the earlier build (KB5089549), your situation stems from a pre-existing, independent compatibility conflict between Vanguard's kernel-level requirements, Intel virtualization, and your GPU drivers, rather than the specific bug introduced in the May preview.

To ensure all these components are properly aligned with the current system state, I recommend performing the following troubleshooting steps:

  • Update your Intel chipset drivers: Since this involves hardware-level virtualization (HYPERVISOR_ERROR), keeping your Intel chipset drivers fully up to date is crucial for proper communication between the OS and the processor. You can download the latest version directly from your motherboard manufacturer's support page or by using the Intel Driver & Support Assistant.
  • Perform a clean reinstall of Riot Vanguard: Completely uninstall Vanguard, restart your PC, and then launch Valorant to allow the anti-cheat to deploy a fresh installation. This ensures that no corrupted temporary files or driver cache from the previous OS build are persisting.
  • Perform a clean installation of your GPU drivers: Use the tool DDU (Display Driver Uninstaller) in Safe Mode to remove the existing Nvidia drivers before installing the latest official release.

If you need more details on any of these suggestions, let me know.

Feel free to ask any questions you may have.

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  1. AI answer

    2026-06-12T16:54:30.73+00:00

    KB5094126 is a security update; if blue screens persist after installing it, the issue is likely not fully resolved by that update on the specific device and further troubleshooting is required.

    For repeated blue screens such as HYPERVISOR_ERROR and KMODE_EXCEPTION_NOT_HANDLED when starting a specific game with kernel-level anti-cheat, follow the basic Windows 11 stop error steps:

    1. Remove any recently added hardware, then test again.
    2. Try starting Windows in Safe Mode and verify that the system is stable there. If it is, the cause is likely a driver or software component that only loads in normal mode.
    3. In Device Manager, look for devices with an exclamation mark, update their drivers, or temporarily disable/uninstall them, then test Valorant again.
    4. Ensure there is at least 10–15% free space on the system drive so Windows can create and use paging/swap files correctly.
    5. Install all latest Windows 11 updates beyond KB5094126 (Settings → Windows Update → Check for updates) so that any additional fixes for virtualization, kernel, or driver compatibility are applied.
    6. If the issue started recently and persists, use a recovery option such as System Restore to roll back to a point before the crashes, or another recovery method that fits the situation.

    If the problem continues after these steps, advanced troubleshooting of blue screens and stop codes is required (for example, analyzing dump files and checking for specific driver conflicts with the anti-cheat), which goes beyond the basic steps and may require IT professional tools.

    References:

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  2. David-M 126.8K Reputation points Independent Advisor
    2026-06-12T17:26:45.7533333+00:00

    Hi. I'm David, and I'm happy to help you.

    Please see if your computer created minidump files.

    These files are in C:\Windows\Minidump.

    (If you don't have a Minidump folder, check if it is in the plural Minidumps.)

    Copy any files you have to your desktop and store them in a ZIP file. Then, upload the ZIP file to the cloud (OneDrive), choose to share it, and get the link.

    Then, post the link to the ZIP file here so I can have a look.

    Looking forward to your reply.

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