Users’ video feeds may not be visible to other attendees when joining a Microsoft Teams meeting

Title: Users’ video feeds may not be visible to other attendees when joining a Microsoft Teams meeting

User impact: Users’ video feeds may not have been visible to other attendees when joining a Microsoft Teams meeting.

More info: Impact was limited to users joining Microsoft Teams meetings through the lobby. Where possible, affected users could bypass impact by joining meetings directly.

The issue occurred from any Microsoft Teams connection method, but it was reported to most commonly occur when using the new Microsoft Teams.

Final status: Our investigation has determined that a recent service change within the Microsoft Teams code base responsible for creating lobbies contained a code issue that prevented users’ video feeds from being visible to other attendees when joining meetings, leading to impact. We’ve reverted the offending change to repair this issue, and our subsequent testing has confirmed that impact is remediated.

Scope of impact: Any user with an enabled video feed who joined a Microsoft Teams meeting may have been impacted.

Start time: Monday, March 25, 2024, at 6:00 AM UTC

End time: Tuesday, April 2, 2024, at 5:00 AM UTC

Root cause: A recent service change within the Microsoft Teams code base responsible for creating lobbies contained a code issue that prevented users’ video feeds from being visible to other attendees when joining meetings, leading to impact.

Next steps:
– We’re further reviewing the offending service change to understand how the code issue was introduced, and to understand what prevented it from being detected in our update testing and validation procedures, which will allow us to prevent similar issues in future updates.

This is the final update for the event.