Problem when starting visual studio solution

What I'm seeing is your test project, test projects are not debugged from the "traditional way."

I do not know if there are other options, but the one I know is by Test Explorer , to open it, search for "test explorer" in the visual studio search box

Afterthis,itwillopenawindow(usuallyontheleftside),casesthetestsdonotappreciate,recompiletheproject.

IalsonoticedthatyouareusingNUnit.ItmaybenecessarytoinstalltheAdapterfromitsothatthetestsappear.

The class library is like a book, in your case the following is happening: The Book is trying to read the Human and not the Human read the Book . Got it?

Human would be the .EXE and the Book would be the Class Library

Since you created a Class Library solution, then in this solution you will only have Class Library. If you create .EXE projects within this solution, it will make mistakes because the solution is like a bookshelf full of projects (books) that was created for the purpose of just storing books and never being started.

To solve the problem, try to create a solution that has a starting point such as wpf , console application ,. ..), then you can create several libraries with a starting point already configured automatically to read the (library).