DllNotFoundException in Unity Mobile

I created a C++ plugin for Unity and I tried to use it in my application. I putting the DLL file into my Unity project’s “Plugins” folder. Also i putting dependencies into Unity/Editor folder. But when i run the game (from Editor) I get DllNotFoundException and “License error. Plugins are only supported in Unity Pro!” errors. My Unity version is 4.0 for Mobile. And the most interesting things, when i put the main dll into Unity/Editor folder, the application trows only one error - “License error” and function from dll works fine. Can any one helps me?

The code that I wrote for the C++ is shown in the following:

#define EXPORT __declspec(dllexport)

#include <stdio.h>

extern "C"
  const EXPORT int DisplayNumber()
    return 42;

C# file:

    public static extern int DisplayNumber();

	// Use this for initialization
	void Start () 
        print("DLL: " + DisplayNumber());

What mobile platform are you running it on? On iOS, your DLL import path (in the C# file) should be “__Internal”.
For Android, the path should be whatever the name of the library is.