This project unofficially supports Silverlight projects in Visual Studio 2026.

Click here for the Visual Studio 2022 version.
Click here for the Visual Studio 2017 and 2019 version.

System Requirements

• Silverlight SDK

  Silverlight 5 SDK 5.0.61118.0
  Size: 11.2 MB
  SHA-256: f52fe767c2290d04b21e8da0ababdf710b7933a976b2eb1c99eea2f5529f6d10

• Silverlight Developer Runtime 5.1.50918.0

  Note: You may need to uninstall any previous versions of the Silverlight Runtime in order to install the Silverlight Developer Runtime.

  Silverlight_Developer.exe (32-bit)
  Size: 8.96 MB
  SHA-256: dbd825b02e45d4ce604a83168b41bfb902510d36fd67b861d54b9913d8902655

  Silverlight_Developer_x64.exe (64-bit)
  Size: 17.0 MB
  SHA-256: a96846b277a3db6f7f5d47cdb8ded8ab2363d1fd3aeb604ed1a4329e1359e56f

Known Issues

Microsoft Visual Studio 2022 introduced a bug causing build errors when a web application references a Silverlight application.
Please vote up the issue here: MSBUILD : error : Copying file failed. Index (zero based) must be greater than or equal to zero and less than the size of the argument list
As a work-around, perform the following steps in the web application:

1. Add a NuGet reference to the package SilverlightWebApplication.Build.Tasks.
2. Edit the *.csproj file and replace:
   <Import Project="$(VSToolsPath)\WebApplications\Microsoft.WebApplication.targets" Condition="'$(VSToolsPath)' != ''" />
   with
   <Import Project="$(VSToolsPath)\WebApplications\Microsoft.WebApplication.targets" Condition="false" />

No XAML designer in Visual Studio or Blend.
Silverlight 5 isn't listed as a target framework when creating a Legacy Portable Class Library (PCL).

Frequently Asked Questions

The Silverlight 4 SDK is not installed.

When building a silverlight project the following compiler error occurs:
C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v5.0\Microsoft.Silverlight.Common.targets(104,9): error : The Silverlight 4 SDK is not installed.

This may be caused by the compiler failing to load a 32-bit assembly reference when compiling the silverlight project targeting "Any CPU" in a 64-bit process. As a work-around, force MSBuild to load task assemblies in the x86 architecture:

1. Update C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v5.0\Microsoft.Silverlight.Common.targets as follows:

   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.GetSilverlightFrameworkPath" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.CompileXaml"  AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.ValidateXaml" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.XapPackager"  AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.CreateSilverlightAppManifest" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.CreateHtmlTestPage" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.ValidateSilverlightFrameworkPaths" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.ValidateXapFilenames" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.CategorizeSilverlightReferences" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   <UsingTask TaskName="Microsoft.Silverlight.Build.Tasks.PackagePlatformExtensions" AssemblyFile="Microsoft.Silverlight.Build.Tasks.dll" Architecture="x86" />
   

1. If the silverlight project uses WCF RIA Services, also update C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v5.0\Microsoft.Ria.Client.targets as follows:

   <UsingTask TaskName="Microsoft.ServiceModel.DomainServices.Tools.CreateRiaClientFilesTask"
             AssemblyName="Microsoft.ServiceModel.DomainServices.Tools, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" Architecture="x86" />

   <UsingTask TaskName="Microsoft.ServiceModel.DomainServices.Tools.CleanRiaClientFilesTask"
             AssemblyName="Microsoft.ServiceModel.DomainServices.Tools, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" Architecture="x86" />
   

Unable to start debugging.

When debugging a silverlight project the following error occurs:
Unable to start debugging. The Silverlight Developer Runtime is not installed.

1. Uninstall Microsoft Silverlight.
2. Install Microsoft Silverlight Developer Runtime 64-bit.
3. Set Internet Explorer as your default browser.

Trademarks and Copyright

Visual Studio and Silverlight are trademarks of Microsoft Corporation.
Visual Studio, Silverlight, and their technology are Copyright © Microsoft Corporation.

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Change Log

v3.0.405.62 (April 5^th, 2026)

• First release for Visual Studio 2026