Error Trying to Download a Image from a Local File

Hi Guys I Need your help.
Im Download a image from a Local File, and before the build the test looks perfect, but when i build it it didnt work, i put the build debug and throw me this:
“You are trying to load data from a www stream which has the following error when downloading Couldn’t open the file”

Anyone know why?
Why it works before build and it wont work after build?

Thanks a lot guys.

 public GameObject quad;
    	Texture2D tex;

The Other Method: 

IEnumerator LoadContent(string path){
		WWW www = new WWW("file:///"+path);
		tex = new Texture2D(64,64);
		yield return www;
		quad.renderer.material.mainTexture = tex;
		Image img = quad.GetComponent<Image> ();
		img.texture = tex;


Sorry guys, i solved myself, i just have to put the PLayer Settings in .Net 2.0

Thanks for reading.