Microsoft's Windows 11 March update is causing sign-in failures for Microsoft account users across multiple applications. The issue affects Windows 11 versions 25H2 and 24H2 with KB5079473 installed, preventing access to apps like Microsoft Teams, OneDrive, Microsoft Edge, and Office applications including Excel and Word. Users encounter error messages claiming they're offline despite having active internet connections.

This connectivity problem stems from a specific network state that the update mishandles, causing Microsoft applications to incorrectly identify devices as disconnected. The issue exclusively impacts Microsoft account users - local account holders remain unaffected. Microsoft recommends restarting affected devices as a temporary fix, though the problem may recur when devices return to the problematic network state.

The company is developing a permanent fix expected to roll out early next week. This latest bug adds to Windows 11's growing list of post-update issues, including reported C: drive access problems on Samsung devices where the 'C: is not accessible - Access denied' error has surfaced. Microsoft attributes the Samsung issue to the Samsung Galaxy Connect application rather than the Windows update itself.