User impact: Users may be unable to view or access Microsoft 365 group calendars and email messages in the Outlook desktop client.

More info: Affected users are part of a Microsoft 365 group and are on versions 16.0.16222.10000 or higher, including the latest February release channel. Some affected users may also notice that impact self-resolves after some time, although impact may also reoccur at a later time. These users may also be unable to perform one or more of the following actions in the Outlook desktop client: 

– Add or access the group mailbox
– Add or access the group calendar
– Add, remove, or edit group members
– Changes to mail items, such as marking as read, archiving, or moving email to other folders.

Until a fix is deployed for this issue, impacted users with access to Outlook on the web can use that connection method to access the impacted group features.

Alternatively, impacted users can revert to Outlook desktop client build 16130.20332. The steps are outlined in the following article: support.microsoft.com/en-us/topic/how-to-revert-to-an-earlier-version-of-office-2bd5c457-a917-d57e-35a1-f709e3dda841

Current status: We’ve initiated the deployment of our fix to the impacted environments and we anticipate that it will complete by our next scheduled update. Users will be prompted by the client when the updated build is available for download and installation, and performing this update will resolve the problem.

Scope of impact: Impact is limited to users of Outlook desktop client versions 16.0.16222.10000 or higher that attempt to access or perform various Microsoft 365 group related actions.

Start time: Sunday, March 19, 2023, at 12:00 AM UTC

Estimated time to resolve: We anticipate that the deployment of the fix will completely saturate the affected environments and fully remediate impact on Tuesday, May 2, 2023.

Root cause: A recent service update is incorrectly triggering an indexer to delete specific values within the Outlook desktop client for some users, resulting in impact.

Next update by: Tuesday, May 2, 2023, at 7:00 PM UTC