How come classes in subfolders in my App_Code folder are not being found correctly?

Question

I am getting the following error when I put class files in subfolders of my App_Code folder:

errorCS0246: The type or namespace name \'MyClassName\' could not be fou

Answer 1

Is it possible that you haven't set the folder as an application in IIS (or your web server)? If not, then the App_Code that gets used is that from the parent folder (or the next application upwards).

Ensure that the folder is marked as an application, and uses the correct version of ASP.NET.