Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may be unable to use Microsoft Outlook Classic while the Microsoft Teams Meeting Add-in is enabled- ONGOING

Announcements Shagufta Naaz

17/03/2026 09:14:00 AM

NHSmail Reference: INC46775188

Microsoft Reference: EX1254044

Issue Status: ONGOING

Issue Description: Some users may be unable to use Microsoft Outlook Classic while the Microsoft Teams Meeting Add-in is enabled.

More info: If Teams Meeting Add-in is disabled then Outlook Classic functions as normal.

As a workaround, users can also perform an Online Repair of Office or update Outlook to the latest version to resolve the issue.

Current Update: 17/03/2026 09:14:00 AM –Microsoft has identified that a previous Outlook build version is causing impact to occur. We’re working with your representatives to ensure that the latest Outlook version is enabled, to mitigate impact.

Scope of impact: Users attempting to use Microsoft Outlook Classic while the Microsoft Teams Meeting Add-in and previous Outlook build version is enabled may be impacted.

Root cause: A previous Outlook build version that is enabled is causing impact to occur.

Next update by: Thursday, March 19, 2025, at 10:30 AM UTC