Outlook crashing when sending an email with a One Drive file link

Products

• Data Loss Prevention Endpoint Prevent

Issue/Introduction

When trying to send an email in Microsoft Outlook that contains a link to a One Drive attachment, it will cause Outlook to crash. This occurs when either the DLP Endpoint Agnet or the SEP plugins are installed in Outlook. This only occurs when using the "Share link" option to share the file and does not occur when using the "Attach as copy" option.

Outlook popup Window appears that says, "Microsoft Outlook has stopped working Windows can try to restart the program." You will not see any specific related error messages in the DLP Endpoint Agent logs.

Environment

Observed on DLP versions 14.6 - 15.1 and Microsoft Outlook Office 365 version 1803.

Cause

This is caused by a Microsoft problem in Outlook with the mso20win32client.dll that is forcing Outlook to crash.

Refer to this Microsoft Doc that shows the Outlook releases and the issues that are fixed for each. This issue is fixed by the "Fix an issue where an application calling the MAPI API could result in a crash."

Resolution

Upgrade Outlook to the latest version for the fix. As of this writing, the latest version is Version 1807: August 14 2018 (Build 10325.20118).