title: C# - Xamarin.Froms.Build.Task.GetTaskAbi - error
body: <p>I have been getting the below error everytime I try to build a Xamarin Forms App.
  Does anyone have a solution to this error.</p>
  
  <p>I have uninstalled and reinstalled VS2017 two times.
  I have deleted all the folder to do a clean install.</p>
  
  <p>Severity    Code    Description Project File    Line    Suppression State
  Error       The "Xamarin.Forms.Build.Tasks.GetTasksAbi" task could not be loaded from the assembly C:\Users\Regardt.nuget\packages\xamarin.forms\3.0.0.446417\build\netstandard2.0\Xamarin.Forms.Build.Tasks.dll. Could not load file or assembly 'netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The system cannot find the file specified. Confirm that the  declaration is correct, that the assembly and all its dependencies are available, and that the task contains a public class that implements Microsoft.Build.Framework.ITask.    App2.Android            </p>