Nook Tablet WWW.LoadFromCacheOrDownload ( obb_file_url ) not work

Hello!
I've an app with modified Google Play OBB Downloader(http://u3d.as/2Qq). When I run it on my Nook Tablet(ver.2.3.4) and finishing download obb file process I've such message in log :

HTML:

loaded file:///data/data/com.myapp.nook/files/main.1.myapp.obb 
Level '' (1) couldn't be loaded because it has not been added to the build settings.
To add a level to the build settings use the menu File->Build Settings...

The code which was called:

Code (csharp):

1.  
2. IEnumerator Load(string path)
3.     {
4.         string uri = "file://" + path;
5.         WWW www = WWW.LoadFromCacheOrDownload (uri, 0);
6.            
7.         yield return www;
8.  
9.         if (www.error != null) {
10.             Debug.Log ("wwww error " + www.error);
11.         } else {
12.             Debug.Log ("loaded "+uri);
13.             Application.LoadLevel (1);
14.         }
15.     }
16.  

I didn't find any solution. Is it problem with url for obb file? Is it a Unity bug on Nook's devices? Have anybody such problem? Any suggestion please.