Microsoft has acknowledged that the Windows 11 24H2 and 25H2 updates are causing disruptions for IIS websites due to a conflict in the Windows HTTP stack driver (HTTP.sys), resulting in “ERRCONNECTIONRESET” errors for localhost loopbacks and IIS connections. The issue affects devices with updates released on or after September 29, including KB5066835 and KB5065789, impacting server-side applications reliant on HTTP.sys and leading to failed IIS websites or blank pages. The problem may vary based on internet connectivity, system timing, or update installation order. Microsoft is working on a permanent solution and has advised IT administrators to implement a known issue rollback (KIR) through Group Policy to restore stability. Additionally, Microsoft has lifted an upgrade block on Windows 11 24H2 devices that was due to a conflict with a third-party driver.