User impact: Users may be unable to access the default add-ins in Outlook.

More info: This issue impacts both the Outlook desktop client and Outlook on the web. Some affected users find that the “My Templates” icon is missing from the Outlook ribbon and others may be unable to find templates in the AppData Microsoft Templates location, even though templates are known to exist and may still be being used by non-impacted users. Some users also report that the Viva Insights add-in is also impacted by this event.

Current status: We’re continuing our comparison of the affected and non-affected users to correlate whether there are additional issues contributing to the impact, which will help us determine our next troubleshooting steps. Due to multiple ongoing add-in functionality issues, the investigation is taking time to complete.

Scope of impact: Some users attempting to access or use the default add-ins within Outlook may be impacted. This information may be updated as our investigation continues.

Root cause: A recent REST API update prevents users from accessing default add-ins in Outlook.

Next update by: Monday, March 30, 2026, at 9:00 PM UTC