Microsoft Teams Outage History

Microsoft Teams Free experienced a major outage lasting approximately 22 days where new users who signed up during the incident window were unable to search for other users, send chats, or make calls due to a backend deployment issue that caused them to bypass required onboarding steps. The problem resulted in affected user profiles appearing as "Unknown users" to others and left accounts in an incomplete state that prevented normal functionality. Microsoft deployed a fix after extensive validation and gradually rolled it out to the affected environment, with monitoring to ensure complete resolution.

A Windows update introduced a regression that caused Microsoft Teams Free users to intermittently be unable to join meetings or access the service, with users seeing authentication error messages stating "We couldn't authenticate you, This could be due to a device or network problem, or Teams could be experiencing a Technical issue." The issue affected multiple Windows versions (25H2, 24H2, 23H2, and 22H2) and lasted 47.3 hours. Microsoft developed a fix to address the regression after determining that configuration changes were not viable, while users could temporarily resolve the issue by restarting their computers.