Microsoft 365 Alert – Service Degradation – Exchange Online – Users may be unable to open email messages saved as a file more than once in the Outlook desktop client – RESOLVED

18/07/2023 08:45:00 AM (GMT)

NHSmail Reference : INC37068366

Microsoft Reference : EX648854

Issue Status : RESOLVED

Issue Description : Users may be unable to open email messages saved as a file more than once in the Outlook desktop client.

More info : This may affect users that have enabled the Microsoft Teams Meeting Add-in for Microsoft Office.

Impacted users can close and reopen the Outlook desktop client to open email messages saved as files. Once an email message saved as a file has been opened, it can’t be opened again until the Outlook desktop client has been closed and reopened.

Final Update : 09/08/2023 08:45:00 AM – Microsoft confirmed that their fix is complete and determined by reviewing service telemetry that this issue is resolved.

Scope of impact : Any user with the Microsoft Teams Meeting Add-in for Microsoft Office enabled that attempts to access an email from a file more than once in the Outlook for desktop client may be impacted.

Root cause : A recent update introduced a code regression that causes email files to be locked by the Microsoft Teams Meeting Add-in for Microsoft Office, resulting in impact.

Next steps : Microsoft are reviewing their validation and update procedures to detect and prevent issues like this prior to deployment in the future.