[away3d] load created away3d project in other project

[Peyvand Akhoundzadeh]

hi. i created away3d simple project and in a new new empty project load 
away3d project.

var loader:Loader = new Loader();
loader.load(new URLRequest("main.swf"));
var _mc:MovieClip = new MovieClip();
_mc.addChild(loader);

but : 

TypeError: Error #1009: Cannot access a property or method of a null object 
reference.
    at away3d.core.render::Clipping/screen()
    at away3d.core.scene::View3D/render()
    at Main()