Importing whole swf (maybe as2)

Hi there, I’m new to the world of openfl. Sorry if my english is bad. My problem is that I try to import an old swf file probably from Macromedia Flash into my OpenFL project. I don’t know the sourcecode or anything, but looks like I don’t have to. Documentation says that I can import whole swf without knowing class names. However i got an error “NULL OBJECT REFERENCE” after compiling the project and than it terminates.

Main.hx:

package;

import openfl.display.Bitmap;
import openfl.display.Sprite;
import openfl.Lib;
import openfl.Assets;

/**
 * ...
 * @author Ian Andrushchuk
 */
class Main extends Sprite 
{

	public function new() 
	{
		super();
		
		Assets.loadLibrary("274", function(_) {
			var clip = Assets.getMovieClip ("274:");
			addChild(clip);
			
			clip.x = 0;
			clip.y = 0;
		});
	}

}

project.xml:

<?xml version="1.0" encoding="utf-8"?>
<project>

	<meta title="Основные элементы электрических схем" package="Основные элементы электрических схем" version="1.0.0" company="Ian Andrushchuk" />
	
	<app main="Main" file="Основные элементы электрических схем" path="bin" />
	
	<window background="#000000" fps="60" />
	<window width="800" height="480" unless="mobile" />
	<window orientation="landscape" vsync="false" antialiasing="0" if="cpp" />
	
	<source path="src" />
	<haxelib name="openfl" />
	<haxelib name="actuate" />
	<haxelib name="swf" />
	<library path="Assets/img/274.swf" />
	
	<icon path="assets/openfl.svg" />
	<assets path="assets/img" rename="img" />
	
</project>

My 274.swf file is in assets/img folder. Project compiles, but with warning [openfl.Assets] There is no asset library named “274”. Please help :cold_sweat: