Microsoft has resolved a significant Multi-Factor Authentication (MFA) outage that temporarily blocked customers from accessing Microsoft 365 Office apps.
The issue, which also affected MFA registration and reset processes, caused disruptions for users relying on MFA for authentication.
Outage Details
The incident was first acknowledged in an alert published via the Microsoft 365 admin center, where Microsoft stated:
"Users may be unable to access some Microsoft 365 Apps when authenticating with MFA. We're redirecting traffic to alternate healthy infrastructure while we continue to investigate the root cause of impact."
The outage was isolated to users authenticating via MFA in Microsoft 365 Office apps.
In a related admin message, Microsoft also noted that some users reported unexpected crashes of Microsoft 365 applications on Windows Server 2016 devices.
The company is investigating telemetry data to pinpoint the root cause and implement a resolution for the affected infrastructure.
Broader Context of Microsoft 365 Outages
This incident follows a series of recent Microsoft 365 disruptions:
- Last Month: A "Product Deactivated" error impacted customers using Microsoft 365 Office apps.
- Earlier Issues: Office web apps and the Microsoft 365 admin center experienced a significant outage.
- November 2024: A global outage affected multiple services, including Microsoft Teams, Exchange Online, SharePoint Online, OneDrive, Purview, Copilot, and Outlook.
Resolution Confirmed
As of January 13 at 05:51 EST, Microsoft declared the MFA issue resolved, attributing the problem to a section of unresponsive infrastructure responsible for MFA operations in Western Europe.
"We've completed an extended period of monitoring in which the service health has remained stable and are declaring this incident as resolved," Microsoft announced.
The company reassured users of stable service availability post-resolution, emphasizing its commitment to maintaining reliable access to its suite of productivity tools.
End Note
While Microsoft has resolved this particular issue, the frequency of outages highlights the growing complexities of managing global cloud services. Users are advised to monitor admin center updates and prepare contingency plans to minimize disruption during future incidents.
