A recent Microsoft Teams update is causing a “Select a certificate” prompt to be displayed to Teams users before they can use the software.
The issue started this morning and causes a “Select a certificate” prompt for us-prod.asyncgw.teams.microsoft.com to be shown while logging into the service.
Microsoft has acknowledged the bug and is tracking the issue under the ‘TM261228’ advisory, where they state a recent update to the software is causing the problem.
“We’ve determined a recent deployment, designed to improve service performance, is inadvertently causing impact. We’re reverting the update while