Current Status: Engineers have identified that a certificate mismatch is causing the issue and are presently working with Azure engineers to deploy the proper certificate across the affected environment.
User Experience: Affected users are unable to sign in to Yammer using the Single Sign-On (SSO) tool.
Customer Impact: The impact is specific to users who utilize the Azure identity provider for SSO authentication. Impact appears to be limited at this time.
Preliminary Root Cause: A certificate mismatch between the Yammer and Azure environment is preventing some customers from signing in to the Yammer service.