Current Incident - Can't access Microsoft 365 services

Microsoft is reporting that Office 365 service was restored last night (Monday, September 29) around 9:30 p.m.

Preliminary root cause: A code issue caused a portion of our infrastructure to experience delays processing authentication requests, which prevented users from being able to access multiple M365 services.

Next steps:

• Microsoft is reviewing their code to understand what caused the code to stop processing authentication requests in a timely fashion.

Microsoft will publish a post-incident report within five business days.

Current status: Our mitigation strategy was successful in allowing users to sign into the previously impacted services. Our internal monitoring has validated this recovery and we have received positive confirmation from customer reports. We’ll continue to monitor the service and provide updates on full recovery to remaining impacted users.

More info: Users would be unable to access Outlook.com, Microsoft Teams including Teams Live Events, and Office.com. Additionally, Power Platform and Dynamics365 properties are affected by this incident.

Existing customer sessions are not impacted and any user who is logged in to an existing session would be able to continue their sessions.

Current status: We've identified that reverting the recent change did not alleviate impact to Microsoft services as expected. We're working to explore additional options for mitigation.

Scope of impact: Any user may experience access problems for Microsoft 365 services.

User Impact: Users may be unable to access multiple Microsoft 365 services.

More info: Any Microsoft 365 service that leverages Azure Active Directory (AAD) authentication may be impacted by this issue.

Current status: We've identified and are reverting a recent change to the service which may be causing or contributing to impact.

Scope of impact: Any user may experience access problems for Microsoft 365 services.