Office 365 service health status
Title: Unable to sign in to Microsoft 365 services
User impact: Affected users may be unable to sign in using Multi-Factor Authentication (MFA).
More info: Users may also be unable to carry out self-service password resets.
Current status: We've confirmed that MFA requests are being processed successfully. We're continuing to monitor the service to ensure that impact has been remediated.
Scope of impact: Impact may be experienced by users accessing Office 365 services via Multi-Factor Authentication.
Start time: Monday, November 19, 2018, at 4:39 AM UTC
Preliminary root cause: A recent update to the MFA service introduced a coding issue that prevented users from being able to sign in or carry out self-service password resets when using MFA for authentication.
Next update by: Tuesday, November 20, 2018, at 6:00 PM UTC
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