An Explosion of Audit Events for Legacy SharePoint Online Authentication

IDCRL events in audit log.

Microsoft phased out the legacy IDCRL authentication mechanism from SharePoint Online on May 1, 2026. Sounds good, until you notice the explosion of IDCRLBlockedDueToSoftEnforcement events created by SharePoint Online in the unified audit log. The events are associated with Microsoft Office apps like Word, which SharePoint appears to think are still using IDCRL. For whatever reason, the audit log is now cluttered with unwanted events generated by the interaction between SharePoint and Office.