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Article ID: 2512827 - Last Review: June 21, 2014 - Revision: 2.0

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Microsoft Silverlight is a cross-browser, multi-environment plug-in that delivers the next generation of Microsoft .NET–based media experiences and rich interactive applications for the web. This article describes Silverlight 4 general distribution release version 4.0.60531.0. This update was released on Jun 14, 2011.

Silverlight update information

An update is available for Microsoft Silverlight. This update offers a new build (version 4.0.60531.0) that is an upgrade to earlier versions of Silverlight. This update is included in current Silverlight installers. If your computer does not have Silverlight installed, the installer will be offered to you by Microsoft Update or by Windows Server Update Services (WSUS). The WSUS Feature Pack will be available soon.

Installation information

This update is available from the following sources.

Silverlight site

The Silverlight installer includes all earlier updates in addition to this update. To install the latest version of Silverlight on your computer, visit the following Microsoft website:

Microsoft update

This update is also available to users of Microsoft Update. If you have an earlier version of Silverlight installed on your computer, this update will be offered as "Update for Microsoft Silverlight (KB 2512827)."

How to uninstall Silverlight

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How to hide this update so that it does not appear again

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More information

Issues that are fixed by this update

Issue 1

Security issue described in the following Microsoft Knowledge Base article:

2514842  ( )   MS11-039 : Vulnerability in the .NET Framework and in Microsoft Silverlight could allow remote code execution: June 14, 2011  

Issue 2

You cannot use the keyboard to press a Silverlight button in Apple OS X 10.6 or in Firefox 4.0.

Issue 3

Consider the following scenario:
  • You have a computer that is connected to multiple monitors.
  • You open a Silverlight page by using Firefox 4.0.
  • You move the page to another monitor.
  • You try to view the page in full-screen mode.
In this scenario, the page is displayed in full-screen mode on the previous monitor.

Issue 4

Consider the following scenario:
  • You have Windows Internet Explorer 8 together with Silverlight 4 GDR 1 or a later version of Silverlight installed on a computer.
  • You run a Silverlight 4 GDR 1 application that contains a custom binding on the computer. The binding has a polling duplex binding element that uses a MultipleMessagesPerPoll value. This value is used during duplex communication.
  • The HTTP stack is set to use the BrowserHttpWebRequest object.
  • A poll reaches the ServerPollTimeout value and times out, and no operation originates from the client-side.
In this scenario, an error occurs.

Issue 5

Assume that a Silverlight 4-based application has a DependencyObject object that is set from a StaticResource markup extension. The markup extension is in a template. When you run the application, a memory leak occurs in the template.

Feature that is added by this update

An InjectClientInformation property is added to the LicenseAcquirer class of the System.Windows.Media namespace. The property injects a collection of hashed pseudo-unique Base64 string values to a license challenge on a per-domain and per-computer basis.

Instructions for using InjectClientInformation in your development environment
  1. Install the Silverlight Runtime
  2. Copy System.Windows.dll from C:\Program Files\Microsoft Silverlight\4.0.60531.0
  3. Paste a copy of System.Windows.dll into C:\Program Files\Reference Assemblies\Microsoft\Framework\Silverlight\v4.0Start VS 2010 and build/rebuild your project


For more information about Silverlight, visit the following Microsoft websites:
Silverlight administration (
Microsoft Silverlight (
Silverlight developer resources (
To report issues about this update, or to send any feedback to the Microsoft Silverlight development team, visit the following Microsoft website:
Microsoft Connect (
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

Applies to
  • Microsoft Silverlight 4
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