title: Cannot install MvvmCross - CrossCore - Portable support in Xamarin Studio 4.2.2
body: <p>I created the Portable Class Library project but I cannot install the Portable support Mvvmcross plugin into it.</p>
  
  <p>I'm getting the following error:</p>
  
  <pre><code>------- Installing...MvvmCross.PortableSupport 3.1.1 -------
  Adding 'MvvmCross.PortableSupport 3.1.1' to Prototype.Core.
  Could not install package 'MvvmCross.PortableSupport 3.1.1'. You are trying to install this package into a project that targets 'portable-win+net45+sl40+wp71', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.
  System.InvalidOperationException: Could not install package 'MvvmCross.PortableSupport 3.1.1'. You are trying to install this package into a project that targets 'portable-win+net45+sl40+wp71', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.
     at NuGet.ProjectManager.ExtractPackageFilesToProject(IPackage package)
     at NuGet.ProjectManager.AddPackageReferenceToProject(IPackage package)
     at NuGet.ProjectManager.Execute(PackageOperation operation)
     at NuGet.ProjectManager.Execute(IPackage package, IPackageOperationResolver resolver)
     at NuGet.ProjectManager.AddPackageReference(IPackage package, Boolean ignoreDependencies, Boolean allowPrereleaseVersions)
     at NuGet.ProjectManager.AddPackageReference(String packageId, SemanticVersion version, Boolean ignoreDependencies, Boolean allowPrereleaseVersions)
     at ICSharpCode.PackageManagement.SharpDevelopPackageManager.AddPackageReference(IPackage package, Boolean ignoreDependencies, Boolean allowPrereleaseVersions)
     at ICSharpCode.PackageManagement.SharpDevelopPackageManager.InstallPackage(IPackage package, InstallPackageAction installAction)
     at ICSharpCode.PackageManagement.PackageManagementProject.InstallPackage(IPackage package, InstallPackageAction installAction)
     at ICSharpCode.PackageManagement.InstallPackageAction.ExecuteCore()
     at ICSharpCode.PackageManagement.ProcessPackageAction.Execute()
     at ICSharpCode.PackageManagement.PackageActionRunner.Run(IPackageAction action)
     at ICSharpCode.PackageManagement.PackageViewModel.InstallPackage(IEnumerable`1 packageOperations)
     at ICSharpCode.PackageManagement.PackageViewModel.InstallPackage()
     at ICSharpCode.PackageManagement.PackageViewModel.TryInstallingPackage()
  ==============================
  </code></pre>
  
  <p>Please someone help me with this issue.</p>
  
  <p>==============================</p>
  
  <p>Added:</p>
  
  <p>Some details about the system:
  Windows 7 x64, NO Visual Studio installed, Portable Libraries installed manually with /buildmachine key, .NET Framework 4.5 is up to date.</p>