Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may see unwanted add-ins appearing automatically across all Outlook clients – ONGOING

12/08/2026 09:12:00 AM

NHS.net Connect Reference: INC46907040

Microsoft Reference: EX1441488

Issue Status: ONGOING

Issue Description: Some users may see unwanted add-ins appearing automatically across all Outlook clients.

More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed.

Current Update: 02/09/2026 09:15:00 AM – Microsoft is coordinating with a subset of affected users who are performing the actions needed to remediate the impact to ensure that running the command and installing previously installed apps fully resolves the issue.

Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses.

Root cause: A portion of the Exchange Online add-in sync pipeline isn’t processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact.

Next update by: Friday, September 4, 2026, at 6:30 PM UTC