Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients

Title: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients User impact: Users may have intermittently been unable to launch Microsoft Teams from the web or desktop clients. Final status: Following an extended period of monitoring the service health telemetry, we’ve confirmed that impact has been remediated. Scope of impact: Some users may have intermittently been unable to launch Microsoft Teams from the web or desktop clients. Start time: Wednesday, September 16, 2026, at 3:00 AM UTC End time: Thursday, September 17, 2026, at 11:12 AM UTC Root cause: A recent update introduced an issue affecting a component responsible for launching the app and resulted in the impact. Next steps: - We’re continuing to analyze how the recent service update was applied to understand why the potential for impact wasn't caught during the update testing and validation phase. These actions will help us to clarify what actions we can take to ensure that similar impact doesn't occur in the future and to continue our ongoing mission to improve the resilience of our service for all Microsoft Teams users. This is the final update for the event.

Title: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients User impact: Users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. Current status: We've confirmed that the issue is associated with a recent build update and have expanded our mitigation efforts by rolling affected deployments back to a last-known-good build. We've also implemented measures to prevent further rollout of the affected update while we continue monitoring service health and validating the effectiveness of the mitigation. Scope of impact: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. This information may be updated as our investigation continues. Start time: Wednesday, September 16, 2026, at 3:00 AM UTC Root cause: A recent update introduced an issue affecting a component responsible for launching the app, resulting in the impact. Next update by: Friday, September 18, 2026, at 6:30 AM UTC

Title: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients User impact: Users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. Current status: We’ve determined that a recent update introduced an issue affecting a component responsible for launching the app, resulting in the impact. We’ve initiated the reversion of the problematic update and will provide an estimated completion time once available. Scope of impact: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. This information may be updated as our investigation continues. Start time: Wednesday, September 16, 2026, at 3:00 AM UTC Root cause: A recent update introduced an issue affecting a component responsible for launching the app, resulting in the impact. Next update by: Thursday, September 17, 2026, at 9:00 AM UTC

Title: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients User impact: Users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. Current status: We suspect that a recent build update introduced this issue and we’re reviewing options to revert the offending changes to potentially remediate the impact. Scope of impact: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. This information may be updated as our investigation continues. Next update by: Thursday, September 17, 2026, at 7:00 AM UTC

Title: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients User impact: Users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. Current status: We're investigating a potential issue in which some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients and checking for impact to your organization. We'll provide an update within 30 minutes.