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Article ID: 2526954 - Last Review: June 17, 2011 - Revision: 3.0

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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 version 4.0.60310.0 of Silverlight 4. This update is a general distribution release and was released on April 19, 2011. 

Silverlight update information

An update is available for Microsoft Silverlight. This update offers a new build (version 4.0.60310.0) 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 2495644)."

How to uninstall Silverlight

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

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Issues that are fixed by this update

Issue 1

Consider the following scenario:  
  • You call the HtmlPage.RegisterScriptableObject method to register an instance of a scriptable type.
  • You run a Silverlight 4 application to enable a JavaScript-based script to access the members of the scriptable type.
  • The application is displayed in a modal window. 

In this scenario, you receive the following warning message:
This page has an unspecified potential security risk. Would you like to continue?
Note This issue typically occurs when a Microsoft office 365 user uses Microsoft SharePoint Online. 

Issue 2

Consider the following scenario:  
  • You create a user control that inherits from Control in a Silverlight 4 application. The user control overrides DefaultStyleKey and adds one DependancyProperty.
  • The ControlTemplate property of the control contains a pop-up control that has a single ContentPresenter object. 
  • The object is bound to the custom DependencyProperty property by using the TemplateBinding function.
  • The pop-up control is never opened. 

In this scenario, the memory of the popup control is not garbage-collected. Therefore, a memory leak occurs. 

Issue 3

Consider the following scenario:  
  • You open a Silverlight 4 application by using Windows Internet Explorer 9.
  • You switch the window to full-screen mode and then restore the window to the original size.

In this scenario, the contents of the window may be displayed incorrectly. For example, a blank area appears in the window. The issue occurs because the BrowserInteropHelper class incorrectly reports the number of child entries for an element in the host HTML page. 

Issue 4

Assume that you are running a Silverlight 4 application that contains a DataGrid control. The columns in the control are not the same width. In this scenario, the rows of the control are garbled when you scroll horizontally through the control.

Issue 5

Consider the following scenario:  
  • You run a Silverlight 4 application that contains a DataGrid control.
  • The control is bound to a type that uses the INotifyDataErrorInfo interface for validation.
  • Multiple event subscriptions are made to the INotifyDataErrorInfo.ErrorsChanged event.
 In this scenario, the memory of the DataGrid control is not released. Therefore, a memory leak occurs. 

Issue 6

Assume that the target element of a BindingExpression instance is a TextBlock element or a TextBox element of a DataGridCell object in a Silverlight 4 application. In this situation, the memory of the DataGrid control is not released when you run the application and edit the element. Therefore, a memory leak occurs. 

Feature that is added by this update 

This update adds a feature that sets the InnerException property on the IsolatedStorageException type if a registry key is configured in the following location: 

The value of the registry key is a comma-separated list of domains.


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 (

  • Microsoft Silverlight 4
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