Compilation errors when updating a referenced .net 4.5.2 project in asp.net mvc core app

Question

I currently have a regular 4.5.2 project, which has a class (let's say MyClass with a method)

public static void Do(string name, List<Operation> operations)
        {
            //do some stuff
        }

In my ASP.NET Core MVC app I have

MyClass.Do(User.Identity.Name, operations);

When I try and build this project, I get an error CS1501, No overload for Do takes 2 arguments.

I recently updated Do to add the string name argument. In fact, any changes I make to the .net 4.5.2 assembly are reflected in Visual Studio, are built into the assembly, but when I build (or clean/build, or delete the bin folder), these changes cause compilation errors.

I've also tried removing the project as a reference from the asp.net core project.

What could be causing asp.net mvc to be stuck on the old definition?

UPDATE After some closing/reopening, I've noticed that the paths of my dlls (my referenced projects) are incorrect project.fragment.lock.json.

I don't know what this file is, but it's pointing to bin/Debug/my.dll instead of bin/x64/Debug/my.dll.

If I try to change it manually, it's updated during the next build to the incorrect values.

Answer 1

I've had some odd issues in ASP.NET Core as well. In some cases, the build appears to run without generating any errors, but it never actually builds the project. So you may be actually running the old code even though it acts like you rebuilt it.

When I have had this problem, it has usually been traced down to a problem with references in the project.json. Look to see if there are any "squigglies" in there. Sometimes they wouldn't show up for me until I closed Visual Studio and re-opened the project.