title: How can I retarget the framework for a .NET Core application in Visual Studio 2015?
body: <p>I created an empty web project with ASP.NET Core in Visual Studio 2015, but I got a build error:</p>
  
  <blockquote>
    <p>Error    MSB3644    The reference assemblies for framework
    ".NETFramework,<strong>Version=v4.5.1" were not found</strong>. To resolve this,
    install the SDK or Targeting Pack for this framework version <strong>or
    retarget your application to a version of the framework for which you
    have the SDK or Targeting Pack installed</strong>. Note that assemblies will be
    resolved from the Global Assembly Cache (GAC) and will be used in
    place of reference assemblies. Therefore your assembly may not be
    correctly targeted for the framework you
    intend.    G:\projects\temp\WebApplication4\src\WebApplication4\WebApplication4.xproj    C:\Program
    Files
    (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets    1098</p>
  </blockquote>
  
  <h3>File <em>project.json:</em></h3>
  
  <pre><code>{
    "dependencies": {
      "Microsoft.NETCore.App": {
        "version": "1.0.1",
        "type": "platform"
      },
      "Microsoft.AspNetCore.Diagnostics": "1.0.0",
  
      "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
      "Microsoft.AspNetCore.Server.Kestrel": "1.0.1",
      "Microsoft.Extensions.Logging.Console": "1.0.0"
    },
  
    "tools": {
      "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
    },
  
    "frameworks": {
      "netcoreapp1.0": {
        "imports": [
          "dotnet5.6",
          "portable-net45+win8"
        ]
      }
    },
  
    "buildOptions": {
      "emitEntryPoint": true,
      "preserveCompilationContext": true
    },
  
    "runtimeOptions": {
      "configProperties": {
        "System.GC.Server": true
      }
    },
  
    "publishOptions": {
      "include": [
        "wwwroot",
        "web.config"
      ]
    },
  
    "scripts": {
      "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
    }
  }
  </code></pre>
  
  <p>I have .NET 4.6 &amp; 4.6.1 SDK installed. How can I retarget the framework to 4.6.1?</p>
  
  <p>After reinstalling 4.5.1 SDK, the error is gone. But I still want to retarget to a newer version.</p>