Global Microsoft outage brings down Teams, Office 365 and Outlook
https://www.theguardian.com/technology/2020/sep/29/major-microsoft-outage-brings-down-office-365-outlook-and-teams
Microsoft says a recent update has affected the processing of authentication requests, making cloud-based services inaccessible
Microsoft has said it is investigating an outage that brought down Microsoft’s cloud-based office services including the meetings software, Teams, worldwide.