Live status of all services Advisory · resolved

Users and admins couldn't view or manage device group configurations through the Microsoft Defender portal

Microsoft 365 suite MO1515549

Users and admins couldn't view or manage device group configurations through the Microsoft Defender portal.

Status
Service restored
Feature
Company or User Administration
Region
Not specified (all regions)
Started
Oct 19, 2026, 20:35 CEST
Resolved
Oct 19, 2026, 21:54 CEST
Duration
1 h 19 min

More info

The device groups page in the Microsoft Defender portal wasn't loading for affected users and admins. Core security operations such as detection, alerting, and incident response weren't affected.

Scope of impact

Users and admins who attempted to view or manage device group configurations through the Microsoft Defender portal may have been affected.

Root cause

A code issue in the device groups page was causing a component in the page rendering process to fail to handle the response correctly and was resulting in the page to crash.

Next steps:
- We're investigating the code issue to pinpoint why it wasn't caught during the testing and validation phase so that we can prevent impact to viewing or managing device group configurations through the Microsoft Defender portal in the future.

This is the final update for the event.

Final status

Our investigation has further determined it was specifically a code issue that was occurring within the device groups page and caused a component in the page rendering process to fail to handle the response correctly and resulted in the page to crash. We've developed and deployed a fix to remediate the impact and confirmed with some affected users that the issue is resolved.

Timeline

Every update Microsoft posted for this issue, newest first.

  1. Oct 19, 2026, 22:03 CEST

    Our investigation has further determined it was specifically a code issue that was occurring within the device groups page and caused a component in the page rendering process to fail to handle the response correctly and resulted in the page to crash. We've developed and deployed a fix to remediate the impact and confirmed with some affected users that the issue is resolved.

  2. Oct 19, 2026, 21:14 CEST

    We've identified that an issue in the device groups page is causing a component in the page rendering process to fail to handle the response correctly and is resulting in the page to crash. We're working on developing a solution that remediates the impact.

  3. Oct 19, 2026, 20:48 CEST

    We're investigating a potential issue with Microsoft Defender portal and checking for impact to your organization. We'll provide an update within 30 minutes.

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Source: Microsoft Graph, Service Communications API. This is the view of a Swiss Microsoft 365 tenant: services not licensed there are missing, and individual issues may affect your tenant differently. Microsoft names the region only in the issue text. The Switzerland view shows issues for Switzerland, for Europe in general and those without a region, but not issues that only name other countries such as Germany or the UK. This page is not provided by Microsoft.