21CTO

Oct 20, 2025 · Backend Development

Why the Latest Windows 11 Update Breaks Local Web Servers and How to Fix It

A recent Windows 11 October update (KB5066835) disables local web server functionality by breaking HTTP.sys, causing ASP.NET developers to lose localhost access, with workarounds like uninstalling the patch or disabling HTTP/2, and highlighting broader migration challenges from Windows 10 to Windows 11.