Microsoft Fixes Windows 11 Bug That Broke Local HTTP/2 Connections

When you purchase through links on our site, we may earn an affiliate commission.

Even though Windows has evolved into a reliable and feature-rich operating system, it’s not immune to the occasional glitch. Ironically, many of these issues often appear right after installing patches meant to fix other problems.

Still, Microsoft’s quick response and commitment to maintaining system stability continue to stand out—especially in cases like the recent network connectivity bug affecting Windows 11.

According to Bleeping Computer, Microsoft has now resolved an issue that disrupted HTTP/2 connections to localhost and websites using Internet Information Services (IIS).

The Source of the Proble

Microsoft has fixed an issue that broke HTTP/2 connections to localhost and websites that use IIS

Image of an error in Windows 11
Microsoft fixes a bug that affected network connections in Windows 11
Users began reporting connection errors on Windows 11 and Windows Server 2025 after installing recent updates—specifically patches KB5066835 and KB5065789. Affected users encountered messages such as “ERR_CONNECTION_RESET” or “ERR_HTTP2_PROTOCOL_ERROR” when trying to load IIS sites or run applications connected to local IP addresses (127.0.0.1).The bug didn’t just impact developers—it also affected desktop applications like Duo and Visual Studio, leading many users to report the issue directly to Microsoft through various channels.

Microsoft’s Investigation and Fix

After investigating, Microsoft traced the problem back to a bug in HTTP.sys, the web server component that supports ASP.NET Core. The company explained that, under certain conditions, this flaw prevented IIS-based websites from loading correctly or caused them to crash altogether.

To address the issue, Microsoft rolled out a fix through Windows Update and shared the following steps for affected users:

  1. Open Windows Update from system settings.
  2. Click Check for updates.
  3. Install any available updates.
  4. Restart your computer once installation is complete.

Following these steps should restore proper connectivity, according to Microsoft.

A Continued Commitment to Improvement

Alongside this fix, Microsoft also patched several other issues, including those affecting unmanaged commercial devices. These efforts highlight the company’s ongoing focus on improving Windows performance, reliability, and security.

While bugs are an inevitable part of software development, Microsoft’s swift response and transparency demonstrate its determination to ensure that Windows remains a stable and evolving platform for users worldwide.

TAGGED:
Share This Article
Author
Follow:
Rohit is a certified Microsoft Windows expert with a passion for simplifying technology. With years of hands-on experience and a knack for problem-solving, He is dedicated to helping individuals and businesses make the most of their Windows systems. Whether it's troubleshooting, optimization, or sharing expert insights,
Leave a Comment