Global fault with Office 365

By Przemek

Teams and exchange online could not work for some users

We've identified an issue with a recent change to an authentication system. We’re rolling back the update to mitigate impact, which we expect will take approximately 15 minutes. Additional information can be found at https://t.co/AEUj8uAGXl or under MO244568 if available.
— Microsoft 365 Status (@MSFT365Status) March 15, 2021

http://status.office.com informs:

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

User impact: Users may be unable to access multiple Microsoft 365 and Azure services, including the Service Health Dashboard.

More info: Initial reports indicate that primary impact is to Microsoft Teams; however, other services including Exchange Online, Intune and Yammer are also impacted.

Posted inSecurity