Windows 11 Update Causes Sign-In Issues for Microsoft Apps

• •The March 2026 Windows 11 update (KB5079473) causes sign-in failures for Microsoft accounts.
• •Affected applications include Teams Free, OneDrive, Edge, Excel, Word, and Microsoft 365 Copilot.
• •Microsoft recommends restarting devices while connected to the Internet as a temporary fix.

Microsoft has acknowledged a significant bug introduced by the March 2026 cumulative update (KB5079473) for Windows 11, which affects sign-ins for Microsoft accounts across various applications, including Teams Free, OneDrive, Microsoft Edge, Excel, Word, and Microsoft 365 Copilot. Users may encounter error messages indicating they are not connected to the Internet, despite being online. This issue is limited to sign-in operations involving Microsoft accounts and does not affect businesses using Entra ID for authentication. Microsoft has suggested a temporary workaround of restarting the device while connected to the Internet, although restarting without an active connection may lead to the same problem. The bug was reported following the March 10 update, and Microsoft is working on a permanent fix. Additionally, two emergency out-of-band updates have been issued to address other issues related to Bluetooth and security flaws. The situation reflects ongoing challenges with Windows updates, as previous months have also seen significant post-update issues.