Final Status: Microsoft identified that a recent update to the Yammer environment caused a configuration issue with the Single Sign-On client. Engineers reverted to a previous configuration of the Single Sign-On system to successfully mitigate impact.
User Experience: The affected users were unable to sign in to the Yammer service with the Single Sign-On client.
Customer Impact: Users that were already signed in to the service were unaffected throughout the duration of the incident.
Incident Start Time: Tuesday, April 7, 2015, at 5:44 PM UTC
Incident End Time: Tuesday, April 7, 2015, at 6:26 PM UTC
Preliminary Root Cause: An update intended to improve the functionality of the Single Sign-on client unexpectedly prevented users from signing in to the Yammer service.
Next Steps: The following is a list of known action item(s) associated with this incident. As part of the Office 365 problem management process, additional engineering actions may be identified to improve the overall service.
– Action: Further investigated the underlying cause of the issue and implement a solution to ensure the problem doesn’t reoccur.
Please consider this service notification the final update on the event.