More info: Impact includes, but may not be limited to, the below services and scenarios. We will update this list as our understanding of the issue progresses.
Microsoft 365 Copilot:
- Users' Copilot prompts that require Microsoft 365 grounding, such as email content, may fail.
OneDrive for Business and SharePoint Online:
-Users may be unable to load or refresh portions of OneDrive and SharePoint, including account and storage information, search results, Favourites, Followed and Shared With Me content, recent files, lists, and news.
-Some users may also experience delayed or failed file opening, Office policy-label retrieval, OneDrive synchronisation, mobile camera upload, and video playback.
-Users may see partial page failures, missing or stale content, repeated retries, and operation timeouts rather than a complete platform outage.
Exchange Online:
-Users may be unable to connect to, or experience degraded functionality, such as failures when attempting to use the search function, within Exchange Online. All connection methods are affected.
Microsoft Teams:
-Users may experience issues with calendar functionality and search. Users’ presence may be stale and not update automatically or through manual adjustment. User location adjustment may fail.
-Microsoft Teams Room (MTR) devices and desktop phones display as offline in the Teams admin center.
Microsoft Purview:
-Users may face intermittent authorisation failures across solutions in Purview. Purview admins can’t access the portal.
Additionally, in Microsoft Purview Communication Compliance, users may see errors when loading Communication Compliance policies and Data Loss Prevention (DLP) policies. Communication Compliance policy creation and evaluation may be delayed.
Microsoft Defender XDR:
-Users may experience intermittent authorisation failures across solutions in Defender.
Microsoft 365 Admin Center:
-Admins may experience issues authenticating into the admin center.
Universal Print:
-Users may be unable to create, upload, or retrieve print jobs.
Current status: Reapplying the targeted authentication component fix and restarting affected infrastructure segments has led to measurable progress. We're observing gradual improvements within telemetry data related to search functionality across the remaining affected infrastructure, and we're continuing this remediation effort across additional infrastructure segments while closely monitoring service health telemetry to ensure we're progressing towards a broader recovery.
Scope of impact: Users attempting to perform any of the outlined impact scenarios may be affected by this event.
Root cause: An issue within a core authentication configuration used by multiple Microsoft 365 services is resulting in impact.
Posted Sep 01, 2026 - 09:20 BST