2025-10-15T10:06:37.1166667+00:00

Recently my local hosted IIS services is not running after the new update. My visual studio projects also can't be run as well. I have to delete the new update in order to run my projects and local hosted services again. May I know what is the problem?

Developer technologies | ASP.NET | Other

Developer technologies | ASP.NET | Other

A set of technologies in .NET for building web applications and web services. Miscellaneous topics that do not fit into specific categories.

  1. 2025-10-15T12:30:02.88+00:00

    Same problem here.

    Had to uninstall KB5066835 AND KB5065789 on hundreds of computers this morning...

    Please fix this issue

  2. 2025-10-15T12:21:53.5266667+00:00

    Same problem here. Had to uninstall KB5066835 AND KB5065789 on 500 computers this morning...

  3. 2025-10-15T10:20:57.7233333+00:00

    Hi Sashi Kumar ,

    Thanks for reporting this. The issue you’re seeing is linked to the October 2025 cumulative update KB5066835 for Windows 11 (builds 24H2 and 25H2). This update introduced security and feature changes, but it appears to have caused IIS (Internet Information Services) to fail or stop responding, which also impacts Visual Studio projects that rely on IIS or IIS Express. [learn.microsoft.com], [stackoverflow.com]

    Summary:

    • After installing KB5066835, many users report:
      • Local IIS sites not loading (ERR_CONNECTION_RESET or ERR_HTTP2_PROTOCOL_ERROR).
      • Visual Studio debugging via IIS Express failing.
    • The root cause seems related to HTTP/2 protocol handling and configuration mismatches introduced by the update. Some reports also suggest IIS config files (applicationHost.config, administration.config) may not update correctly during the patch process. [stackoverflow.com], [learn.microsoft.com]

    My recommendations:

    1. Uninstall KB5066835
      Rolling back the update restores IIS functionality for most users.
      • Go to Settings > Windows Update > Update History > Uninstall Updates.
    2. Disable HTTP/2 in IIS (temporary fix)
      • In IIS Manager, go to Site > Advanced Settings > HTTP/2, and disable it.
    3. Repair IIS Configuration
      • Check C:\Windows\System32\inetsrv\config for corrupted or mismatched files.
      • Restore from C:\inetpub\history or run: sfc /scannow DISM /Online /Cleanup-Image /RestoreHealth
    4. Reinstall IIS Features
      If configs are broken, reinstall IIS via Windows Features.

    #Please submit feedback to Microsoft so they can prioritize a fix:

    • Scroll to the bottom of the KB5066835 page and click Feedback.
    • Include:
      • Update version: KB5066835
      • Symptoms: IIS not starting, Visual Studio projects failing
        • Any error codes or Event Viewer logs

    Hope this helps!

    1. 2025-10-15T22:43:36.8+00:00

      I uninstalled KB506683 and 5066835. that fixed the problem. And saved me from heart attack...

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  4. 2025-10-15T12:05:48.1133333+00:00

    same issue, resolved after uninstall it along with KB5065789

  5. 2025-10-15T12:17:13.86+00:00

    Same problem, uninstalling the update KB5066835 solves it!

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