Microsoft blames a configuration change for Exchange Admin Center tumble
Microsoft restored access to the Exchange Admin Center after a configuration change caused errors that prevented administrators from using the service. The incident matters because the EAC is used to manage Exchange Online mailboxes and groups, and Microsoft said affected administrators had no workaround while it investigated.
Microsoft first reported the issue at 09:37 UTC on 12 October, then traced it to unexpected HTTP responses in the affected request path. Reverting the change restored service; Microsoft said it would review the change and improve monitoring. The outage was resolved before the end of the working day, with a preliminary incident report due within two business days and a final report due the following week.
- A configuration change blocked access to the Exchange Admin Center.
- Microsoft restored service by reverting the change.
- Incident reports are due within two business days and next week.
New here? Start with this
The Exchange Admin Center is Microsoft's tool for managing email accounts and groups within Exchange Online, the company's email service. System administrators—the people who manage a company's email systems—use it daily to add users, manage permissions and resolve email issues.
A configuration change made by Microsoft on 12 October accidentally broke the Exchange Admin Center, preventing administrators from accessing it and leaving them with no way to work around the problem. The issue started at 09:37 UTC when unexpected error messages prevented the tool from functioning properly.
Microsoft identified the faulty configuration change and reverted it to restore service later that same day. The company plans to review what went wrong, improve its monitoring systems to catch similar issues sooner, and provide detailed incident reports to affected customers.