As experienced on March 15th logging into uniFLOW Online with your Microsoft credentials may have failed. This was down to a global outage experienced by Microsoft impacting their ability to service identity provider end points among other services. This was not affecting our other supported identity service providers (Okta, PingIdentity, etc). For organizations that have access to multiple identity providers this could be an option for the future to ensure you retain access in the event one service goes offline.
Please find below the Post Mortem/Root Cause published by Microsoft for the March 15th outage.