title: The current .NET SDK does not support targeting .NET Standard 2.0
body: <p>I upgraded my Visual Studio version to 15.5.2 last night. Now I can no longer run Xamarin.Forms cross platform apps.  They were working fine with no errors before.</p>
  
  <p>When I create a project the option for .NET Portable Class Library is no longer available, and has been replaced with the .NET standard library option.  </p>
  
  <p><a href="https://i.stack.imgur.com/hnTYB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hnTYB.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/FUTjQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FUTjQ.png" alt="enter image description here"></a></p>
  
  <p>However the template project that visual studio creates doesn't work.  It gives me all these errors.  I don't know what to do to fix this, I tried installing the latest .NET Core SDK based on this answer </p>
  
  <p><a href="https://stackoverflow.com/a/45737766">https://stackoverflow.com/a/45737766</a></p>
  
  <p>but it had no effect.  </p>
  
  <p>1.</p>
  
  <blockquote>
    <p>Severity  Code    Description Project File    Line    Suppression State
    Error     The current .NET SDK does not support targeting .NET Standard
    2.0.  Either target .NET Standard 1.6 or lower, or use a version of the .NET SDK that supports .NET Standard 2.0. Phoneword   C:\Program
    Files (x86)\Microsoft Visual
    Studio\2017\Community\MSBuild\Sdks\Microsoft.NET.Sdk\build\Microsoft.NET.TargetFrameworkInference.targets 126</p>
  </blockquote>
  
  <p>2.</p>
  
  <blockquote>
    <p>Severity  Code    Description Project File    Line    Suppression State
    Error     The "ResolveLibraryProjectImports" task failed unexpectedly.
    System.IO.FileNotFoundException: Could not load assembly 'Phoneword,
    Version=0.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't
    exist in the Mono for Android profile? File name: 'Phoneword.dll'<br>
    at
    Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(AssemblyNameReference
    reference, ReaderParameters parameters)    at
    Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String
    fullName)    at
    Xamarin.Android.Tasks.ResolveLibraryProjectImports.Extract(DirectoryAssemblyResolver
    res, ICollection<code>1 jars, ICollection</code>1 resolvedResourceDirectories,
    ICollection<code>1 resolvedAssetDirectories, ICollection</code>1
    resolvedEnvironments)    at
    Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute()    at
    Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
    at
    Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext() Phoneword.Android</p>
  </blockquote>
  
  <p>.</p>
  
  <p><strong>EDIT:</strong> The following 4 errors (3 - 7) went away after I installed the Android 8 SDK from the Android SDK manager, then selected it in the 'Compile using Adnroid Version' option'</p>
  
  <p><a href="https://i.stack.imgur.com/2h7AB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2h7AB.png" alt="enter image description here"></a></p>
  
  <p>3.</p>
  
  <blockquote>
    <p>Error NU1202  Package Xamarin.Android.Support.v4 25.4.0.2 is not
    compatible with monoandroid60 (MonoAndroid,Version=v6.0). Package
    Xamarin.Android.Support.v4 25.4.0.2 supports: monoandroid70
    (MonoAndroid,Version=v7.0)</p>
  </blockquote>
  
  <p>4.</p>
  
  <blockquote>
    <p>Error NU1202  Package Xamarin.Android.Support.v7.CardView 25.4.0.2 is
    not compatible with monoandroid60 (MonoAndroid,Version=v6.0). Package
    Xamarin.Android.Support.v7.CardView 25.4.0.2 supports: monoandroid70
    (MonoAndroid,Version=v7.0)</p>
  </blockquote>
  
  <p>5.</p>
  
  <blockquote>
    <p>Error NU1202  Package Xamarin.Android.Support.v7.AppCompat 25.4.0.2 is
    not compatible with monoandroid60 (MonoAndroid,Version=v6.0). Package
    Xamarin.Android.Support.v7.AppCompat 25.4.0.2 supports: monoandroid70
    (MonoAndroid,Version=v7.0)</p>
  </blockquote>
  
  <p>6.</p>
  
  <blockquote>
    <p>Error NU1202  Package Xamarin.Android.Support.v7.MediaRouter 25.4.0.2
    is not compatible with monoandroid60 (MonoAndroid,Version=v6.0).
    Package Xamarin.Android.Support.v7.MediaRouter 25.4.0.2 supports:
    monoandroid70 (MonoAndroid,Version=v7.0)</p>
  </blockquote>
  
  <p>7.</p>
  
  <blockquote>
    <p>Error NU1202  Package Xamarin.Android.Support.Design 25.4.0.2 is not
    compatible with monoandroid60 (MonoAndroid,Version=v6.0). Package
    Xamarin.Android.Support.Design 25.4.0.2 supports: monoandroid70
    (MonoAndroid,Version=v7.0)</p>
  </blockquote>