Microsoft 365 Alert – Service Degradation – Exchange Online – Users may be unable to access Microsoft 365 apps through the app launcher in Outlook on the web – ONGOING

Announcements Arpan Das

11/12/2025 08:56:00 AM

NHSmail Reference: INC46703259

Microsoft Reference: EX1193572

Issue Status: ONGOING

Issue Description: Users may be unable to access Microsoft 365 apps through the app launcher in Outlook on the web.

Current Update: 12/12/2025 09:21:00 AM – After additional review, Microsoft have determined that to safely remediate the issue for all users in the long-term, they will need to implement a targeted fix rather than reverting the change, and they are preparing the fix for validation now. They are aiming to confirm a timeline for its deployment as it becomes available.

Scope of impact: Some users attempting to access Microsoft 365 apps through the app launcher in Outlook on the web may be impacted. This section may be updated as the investigation progresses.

Next update by: Tuesday, December 16, 2025, at 8:00 PM UTC