Microsoft identified the Teams outage was a result of an expired certificate. They have deployed a new certificate and are restarting related systems which should eventually restore Teams access. Some Drake users might still find that they cannot access Microsoft Teams from all methods. Please try quitting whichever method (desktop app, web application, mobile phone app) is causing issues, and re-opening it to see if access is restored. We will continue to keep you updated as we receive additional information from Microsoft.