I wish to test the core class of a plugin by directly referencing the plugin project and instantiating the plugin class. When I create a test Console App project and add a project reference to the plugin project, I get a warning icon (yellow triangle with exclamation mark) next to the reference in the References list.
When I instead add a reference to the dll, the assembly build output of the plugin, I get no such warning. What could this warning be trying to tell me?
As mentioned in the question's comments, differing .NET Framework versions between the projects can cause this. Check your new project's properties to ensure that a different default version isn't being used.