How to setup Visual Studio to work without CORE symbol?

Prerequisites

• [X] I have written a descriptive issue title

• [X] I have verified that I am running the latest version of Nancy

• [X] I have searched open and closed issues to ensure it has not already been reported

• Nancy version:

• Nancy host

  • [X] Nancy.Hosting.Aspnet

• Environment (Operating system, version and so on): Windows

• .NET Framework version: 4.5.2

Hi, I had never work in a project with multiple targets and compilation symbols. Is it possible to configure Visual Studio to debug Nancy project with non "CORE" code? For instance, the class bellow is disabled to me on Visual Studio: