Two dotnet standard class libraries as dependencies error CS0579

I am getting error CS0579 when I try to put two class libraries as a dependency to a dotnet core MonoGame windows DirectX project. The errors come from a generated source file.

https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/compiler-messages/cs0579?f1url=%3FappId%3Droslyn%26k%3Dk(CS0579)

One class library is a collection of classes or Framework I want to use and which I want to keep seperate.

The second class library is there to hold shared code and content for the different platforms.

So the project structure is very simple:

  1. directx monogame project
  2. opengl desktop monogame project
  3. dotnet core class library targeting net standard for the shared platform code and content
  4. a new dotnet core class library targeting net standard for the small framework / collection of classes I have built in the past

I think combining 3 and 4 would solve everything but I guess I maybe have some configuration
wrong with the dependencies.

Any hint what I should check or an info if in general such a solution dependency structure should work fine would be great. I can provide more info or screenshots if that would help?

Worked it out… The problem was I copied over the old Properties folder with the AssemblyInfo.cs from the old project to project number 4 of the list

grafik

Removing it or as I did set the build action from C# Compiler to None did the trick.