October 4, 2016, update for Outlook 2016 (KB3118375)

Applies to: Outlook 2016

This article describes update KB3118375 for Microsoft Outlook 2016, which was released on October 4, 2016. This update has a prerequisite.

Be aware that the update on the Microsoft Download Center applies to the Microsoft Installer (.msi)-based edition of Office 2016. It doesn't apply to the Office 2016 Click-to-Run editions, such as Microsoft Office 365 Home. (How to determine?)

Improvements and fixes

  • This update rebrands the solutions module to the add-ins module. Introduces a new extension point for web add-ins called module to use solutions module for apps.
  • Translates Module Extension Point feature strings in multiple languages to ensure the accuracy.
  • Corrects the warning information in Russian that is displayed when you schedule a two-day recurrence meeting.
  • Fixes the following issues:
    • After you click a mailto link in an email message in Outlook 2016, certain characters such as brackets or braces in the email message are not displayed correctly. This issue occurs in the English version of Outlook 2016 on a system locale where text such as Arabic or Hebrew is written right-to-left.
    • You can't paste Active Clipboard content in some scenarios.
    • Performance issues with Outlook Add-ins.
    • When you drag-and-drop a folder (folder C) between two other folders  (folder A and folder B) that have sub-folders, folder C will be nested into folder A as a subfolder instead of being inserted between folder A and folder B at the same level.
    • You can now specify the default editor format for calendar items. For more information, see KB3118318.
      Note This only sets the initial default format to be used when a calendar item is created. You can still select another format.
    • When you create a profile in cache mode in Outlook 2016, the cache setup is stuck at 5% or 30%.
    • Folders are sometimes re-synchronized unexpectedly without warning in Outlook 2016. See KB3197761 for details about the new synchronization behavior and controls that is associated with the fix.

How to download and install the update

Microsoft Update

Use Microsoft Update to automatically download and install the update.

Download Center

This update is also available for manual download and installation from the Microsoft Download Center.If you're not sure what platform (32-bit or 64-bit) you're running, see Am I running 32-bit or 64-bit Office? Additionally, see more information about how to download Microsoft support files.

Update information


To apply this update, you must have Microsoft Outlook 2016 installed.

Restart information

You may have to restart the computer after you install this update.

More Information

To determine whether your Office installation is Click-to-Run or MSI-based, follow these steps:
  1. Start an Office 2016 application.
  2. On the File menu, select Account.
  3. For Office 2016 Click-to-Run installations, an Update Options item is displayed. For MSI-based installations, the Update Options item isn't displayed.
Office 2016 Click-to-Run installationMSI-based Office 2016
The screenshot for Word click to run The screenshot for Word MSI


Learn about the standard terminology that's used to describe Microsoft software updates. The Office System TechCenter contains the latest administrative updates and strategic deployment resources for all versions of Office.

File Information

The global version of this update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.