August 11, 2015, update for Outlook 2013 (KB3055012)

Applies to: Microsoft Office 2013 Service Pack 1Outlook 2013Office Home and Student 2013 RT

This article describes update KB3055012 for Microsoft Outlook 2013 that was released on August 11, 2015. This update also applies to Office Home and Student 2013 RT, and that contains Outlook 2013. This update has a prerequisite.

Please be aware that the update in Download Center applies to Microsoft Installer (.msi)-based edition of Microsoft Office 2013. It does not apply to the Office 2013 Click-to-Run editions such as Microsoft Office 365 Home. (How to determine?).

Improvements and fixes

Fixes the following issues:
  • Buttons such as Mark Areas to Keep, Mark Areas to Remove, and Delete Mark are not displayed on the BACKGROUND REMOVAL ribbon in Touch mode in Outlook 2013.
  • After you click a mailto link in an email message in Outlook 2013, certain characters such as brackets or braces in the email message are not displayed correctly. This issue occurs on the English version of Outlook 2013 on a system locale where text such as Arabic or Hebrew is written as right-to-left.
  • After you publish a calendar to a WebDAV server in Outlook 2013, you cannot update the publishing options by using the Change Publishing Options function. Meanwhile, you receive the following error message:
    The address you typed is not valid. Check the address, and then try again.
  • When you try to open a Wunderbar shortcut (the shortcut of the navigation pane) that is created by using object model solutions in Outlook 2013, you receive the following error message:
    An OLE registration error occurred. The program is not correctly installed. Run Setup again for the program.
    Therefore, you cannot delete the Wunderbar shortcut.
  • When you right-click and drag an item from a mailbox folder to the Desktop by using the move function in Outlook 2013, the item is copied but not moved.
  • When you receive and then accept a proposal of a new meeting time for a meeting in Outlook 2013, the meeting time is not updated to the newly proposed time. Instead, it is still set to the original time.
  • If you reply to a custom form with another custom form and this form does not have a message control in Outlook 2013, Outlook 2013 crashes when you send this email.
  • Assume that you change the format of an email message from rich text to HTML in cached mode of Outlook 2013. When you send this email message that has some editing, the email message is sent as the rich text format, and the editing is lost.
  • Allocated graphics objects are not freed in Outlook 2013.
  • When you open, close, and overlay calendars in Outlook 2013, Outlook 2013 crashes.
  • When you try to create a new profile in cached mode in Outlook 2013, you receive the following error message if the .ost file name contains an MS-DOS device driver name:
    Cannot open your default e-mail folders. Unknown Error.
    For the list of default device driver names, see the "MORE INFORMATION" section in article KB74496.
  • When you reply to an email message that is not the latest message in a conversion in Outlook 2013, a mail tip that resembles the following is not displayed:
    You are not responding to the latest message in this conversion. Click here to open it.
    This issue occurs after you apply February 10, 2015, update for Outlook 2013 (KB2956087) .
  • You cannot publish forms to an organizational forms library in Outlook 2013.
  • A password expiration dialog box appears unexpectedly if mailbox users log on to Windows.
  • Store may be corrupted when items are indexed for search in Outlook 2013.

Update information

Restart information

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


To apply this update, you must have Microsoft Office 2013 Service Pack 1 installed.

More Information

How to determine whether my Office installation is Click-to-Run or MSI-based:
  1. Start Outlook 2013.
  2. On the File menu, click Account.
  3. For Office 2013 Click-to-Run installations, an Update Options item is displayed. For MSI-based installations, the Update Options item is not displayed.
Office 2013 Click-to-Run installationMSI-based Office 2013
The screenshot for Outlook Click to Run The screenshot for Outlook MSI


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