NSubstitute -3.x 'ValueType' is defined in an assembly that is not referenced. You must add a reference to assembly 'netstandard,

Question

I am struggling to find a reason behind this error in my code:

ApplicationServiceTests\\Test.cs(29, 13): error CS0012: The type 'ValueType' is defined in an assembly that is not referenced. You must add a reference to assembly 'netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'.

The code line is:

        repo.GetCoveredCards(Arg.Is(cifCode)).Returns(Task.FromResult(new GetCustomerCCPlusResponse()
        {
            CreditCardPlus = new[] { card1, card2 }
        }));

Tools, framework and Package

.net framework 4.6.1 Visual Studio 2015 using MSBuild 14. NSubstitute 3.1.0

It seems like when I use NSubstitute version 1.10.0 and it has worked really well.

Now the question is why am I getting this error with the latest version of NSubstitute?

Answer 1

I had the same issue after updating Visual studio. Delete the bin and obj folders from the UT project folder and rebuild the project. That fixed it for me.