Solution not building due to Xamarin.Forms.Build.Tasks.GetTasksAbi task not loading

I have just installed VS 2017 Community with the Xamarin forms add on. I tried to create a test application for Android and iOS but I cannot get it to build even without touching any of the code.
This is the error I am receiving:
_The "Xamarin.Forms.Build.Tasks.GetTasksAbi" task could not be loaded from the assembly C:\Users....nuget\packages\xamarin.forms\3.1.0.583944\build\netstandard2.0\Xamarin.Forms.Build.Tasks.dll. Could not load file or assembly 'file:///C:\Users...nuget\packages\xamarin.forms\3.1.0.583944\build\netstandard2.0\Xamarin.Forms.Build.Tasks.dll' 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
_
I have tried to change the Xamarin.Forms version to a lower version but this gives the same error.
Anyone know how to get this to work?