Microsoft is facing significant issues with its latest Windows 11 update, which has led to major technical problems for users. The update, identified as KB5066835, has disrupted localhost network connections, rendering many applications and web servers that depend on these connections inoperative. The company is already working on an emergency patch to rectify the situation.
The problems began when the update was rolled out earlier this month as part of Microsoft’s regular security updates. Reports indicate that this update interferes with local network connections, causing application communication failures. Microsoft has acknowledged the issue and is in the process of deploying a hotfix, but it may take up to 48 hours for it to reach all affected devices.
The root of the problem appears to be linked to a regression in HTTP.sys, the kernel-mode HTTP server responsible for managing local and web-based requests within Windows. This regression disrupts the connection handshake process for HTTP/2 services hosted on localhost, leading to what is described as a complete breakdown of related services for developers and IT professionals relying on frameworks like Internet Information Services (IIS) or ASP.NET.
Additionally, users have reported a variety of other issues related to the update, including:
- Installation failures with error codes such as 0x800f0922, 0x800f0983, and others.
- Blocked file previews in File Explorer due to erroneous security warnings.
- Dysfunctional Logitech peripherals.
- Unresponsive mouse and keyboard devices in the Windows Recovery Environment (WinRE), which severely hinders troubleshooting and repair efforts.
The WinRE, which is crucial for diagnosing issues and accessing recovery options, has been rendered nearly unusable as a result of the update, exacerbating the frustration for affected users. While unofficial workarounds have circulated online, Microsoft and tech blogs recommend against such measures due to their potential risks and ineffectiveness.
Despite the setbacks, Microsoft has not issued any formal communication apart from acknowledging the issues, though an emergency update is expected to be rolled out soon. Users are urged to keep checking Windows Update and to restart their machines once the patch becomes available.
These ongoing troubles occur in broader context, as Microsoft recently concluded its free security updates for Windows 10, affecting around 500 million users globally. Those wanting to maintain protection must now subscribe to the Extended Security Updates (ESU) program until 2026. These compounding issues not only highlight the fragility of Microsoft’s system but also prompt users to reevaluate their software reliability as the company pushes users towards newer versions of its operating system.
For more information on the update and associated issues, you can visit Microsoft’s support page.