Assume that you have an application that uses the ShutdownBlockReasonCreate() function to block system shutdown on a computer that is running Windows 8.1, Windows RT 8.1, Windows Server 2012 R2, Windows 8, Windows RT, or Windows Server 2012. The function works correctly for the first time. However, when the application runs the function for the second time, the block reason message is not displayed.
To resolve this issue, install the security update 3002885 that is documented in security bulletin MS14-079.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
See the terminology that Microsoft uses to describe software updates.