Overview
- The out-of-band update addresses a regression from the March 10 KB5079473 release that blocked internet sign-ins in Teams, OneDrive, Outlook, Office apps, Edge and Copilot.
- Microsoft says enterprise sign-ins using Entra ID are not impacted, with the problem primarily affecting consumer Microsoft Account authentication.
- The package appears as “2026-03 Update (KB5085516) (26200.8039)” and raises Windows 11 to Build 26200.8039 on 25H2 and 26100.8039 on 24H2.
- It does not download automatically, and users can install it via Windows Update or use .msu offline installers from the Microsoft Update Catalog.
- Microsoft notes the bug occurs in a specific network connectivity state that can temporarily clear but may return after an offline restart, and the update also includes prior security and non-security fixes.