User impact: Admins may have been unable to access public folders from the Exchange admin center or PowerShell.

More info: Affected admins may have seen the following error message: “Internal server error” when attempting to access public folders from the Exchange admin center or PowerShell.

Additionally, admins may have been unable to run the PowerShell command Get-PublicFolder.

Final status: We’ve confirmed that the code fix has completed deployment to the affected environment and the impact is remediated.

Scope of impact: Impact may have occurred for some admins globally that attempt to access public folders from the Exchange admin center or PowerShell.

Start time: Friday, October 24, 2025, at 7:00 PM UTC

End time: Monday, November 3, 2025, at 12:30 PM UTC

Root cause: A recent service update to improve mailbox folder schema produced an impacting code exception that may have been preventing admins from accessing public folders from the Exchange admin center or PowerShell.

Next steps:
– We’re reviewing our service update procedures to ensure similar issues are caught and addressed in testing ahead of deployment to prevent this from happening again.

This is the final update for the event.