April 5, 2016, update for Outlook 2010 (KB3114996)

Applies to: Microsoft Office 2010 Service Pack 2Microsoft Outlook 2010


This article describes update KB3114996 for Microsoft Outlook 2010, which was released on April 5, 2016. This update has a prerequisite.

Known issues

After you install this update, you may experience the following error when you try to start Microsoft Outlook:

The Windows installer service could not be accessed.

To fix this problem, do one of the following:

  • Option 1: On systems on which update KB3139923 is installed, make sure that update KB3072630 is also installed.
  • Option 2: Uninstall KB3139923.

Improvements and fixes

Fixes the following issues:
  • After receiving the RPC_S_SERVER_TOO_BUSY response from the Exchange Server, Outlook 2010 that has the MAPI over HTTP transport protocol enabled should resend the request after some back-off time instead of immediately reconnecting to the server.
  • When you download email attachments through the MAPI over HTTP transport protocol in Outlook 2010, attachments may be corrupted in some scenarios. This issue occurs in multi-core processor systems and Outlook 2010 with online mode.
  • When a delegate opens a meeting request in Outlook 2010, some respond buttons, such as the Accept, Tentative, and Decline buttons, aren't displayed.

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 Office 2010 Service Pack 2 installed.

Note You may also have to apply Language Pack Service Pack 2 for any Language Packs that you previously installed.

Restart information

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


See the information 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.