This update is no longer available. To fix the issues that are described in this article, install the latest Microsoft Office update from the following Microsoft Docs article:
Update 3213654 for Microsoft Outlook 2016 that was released on June 30, 2017, is not available. The fix that is described in the article is available by installing update 4011052 (Description of the security update for Outlook 2016: July 27, 2017).
Improvements and fixes
This update fixes the following attachment issues that were reported after the release of the June update. For more information, see Outlook known issues in the June 2017 security updates.
When you open an attachment whose file name includes an ellipsis (...) or an exclamation point (!), the files are blocked, and you receive a warning message.
If an email message includes an attached email message, and the subject line of the attached message ends with an unsafe file name extension (as listed in the Blocked attachments in Outlook Office webpage), the email attachment is blocked for recipients.
When you open attachments that use ShowLevel1Attach, you receive the following error message:
One or more objects in this file have been disabled due to your policy settings
The Office System TechCenter contains the latest administrative updates and strategic deployment resources for all versions of Office.