Microsoft 365 Alert – Service Degradation – Exchange Online – Users may be intermittently unable to see app installations or definitions within any Outlook connection method – RESOLVED

08/04/2025 08:30:00 AM

NHSmail Reference: INC46499309

Microsoft Reference: EX1050095

Issue Status: RESOLVED

Issue Description: Users may be intermittently unable to see app installations or definitions within any Outlook connection method.

More info: While Microsoft have confirmed that impact isn’t actively occurring, as of Monday, April 7, 2025, at 5:10 PM UTC, they’re pursuing a solution to ensure this issue doesn’t reoccur.

Final Update: 14/04/2025 09:31:00 AM – After the process of increasing our service’s ability to handle large amounts of traffic completed, they performed an extended period of monitoring service telemetry to ensure that the aforementioned change didn’t bring about any adverse effects and later confirmed that the issue has been resolved.

Scope of impact: Some users attempting to view app installations or definitions within any Outlook connection method may be intermittently affected.

Root cause: A recent change to optimize our service has introduced an issue that resulted in an inordinate amount of traffic volume, causing users to be intermittently unable to see app installations or definitions within any Outlook connection method.

Next steps Microsoft are reviewing this recent service optimization to understand why impact wasn’t identified prior to implementing the change so that we can better understand the underlying issue and improve their change management practices.