Microsoft released an out-of-band update for Windows 11 (KB5085516) on March 21, 2026, to address a sign-in regression introduced by the March 10 cumulative update (KB5079473). Affected users reported being unable to authenticate into apps using personal Microsoft accounts: despite an active internet connection, the sign-in flow incorrectly displayed a “no Internet” error and blocked access to Microsoft services such as OneDrive and Microsoft Teams Free.
Background and scope
The issue is limited to Microsoft account–based authentication. Organizations that rely on Microsoft Entra ID (formerly Azure Active Directory) for app authentication are not affected. Microsoft identified the regression quickly and issued KB5085516 as a cumulative update that includes prior fixes plus the targeted sign-in repair.
What the update includes
– KB5085516: Fix for Microsoft account sign-in failures; available as an LCU (Latest Cumulative Update) for Windows 11 25H2 and 24H2 (OS builds 26200.8039 and 26100.8039).
– KB5083532: A servicing stack update (SSU) for 24H2 (build 26100.8035) to ensure a stable update pipeline during this out-of-band deployment.
– Refreshed AI components: Image Search, Content Extraction, and Semantic Analysis updated to version 1.2602.1451.0 as part of the package.
Deployment and guidance
Microsoft is pushing the fix automatically to devices that already installed KB5079473; devices set to “Get the latest updates as soon as they’re available” will receive KB5085516 automatically. Users can also go to Settings > Windows Update and select Download and install. IT teams using Microsoft Intune or Windows Autopatch should use expedited update workflows provided for rapid, controlled rollout. Microsoft reported no known issues with KB5085516 at the time of the advisory.
Why it matters
This emergency release underscores how cumulative updates can occasionally introduce regressions that impact basic productivity services. Prompt vendor response and clear guidance for consumer and enterprise update channels helped limit disruption for most users.
Licensed under CC BY-ND 4.0 International
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