Cant load texture by WWW in WebGL

Hello. I met that problem only in WebGL build (in Editor mode and WebPlayer everything works fine) Here is code example. In LogViewer I see, that loading not going further "yield return www;"

 private IEnumerator LoadImage()
     {
         WWW www                        = new WWW(url);
         yield return www;
 
         if (www.error == null)
         {
             controller.texture        = www.texture;
         }
         else
         {
             controller.texture        = null;
         }
     }

What is the problem?