OBB expansion files problem

Here's the deal. I've got the Google Play Obb expansion plugin. I've created build with sceneLoader as my 0 scene. I've attached DownloadObbExample script to Main Camera:

 using UnityEngine;
 using System.Collections;
 
 public class DownloadObbExample : MonoBehaviour {
     
     void OnGUI()
     {
         if (!GooglePlayDownloader.RunningOnAndroid())
         {
             GUI.Label(new Rect(10, 10, Screen.width-10, 20), "Use GooglePlayDownloader only on Android device!");
             return;
         }
         
         string expPath = GooglePlayDownloader.GetExpansionFilePath();
         if (expPath == null)
         {
             GUI.Label(new Rect(10, 10, Screen.width-10, 20), "External storage is not available!");
         }
         else
         {
             string mainPath = GooglePlayDownloader.GetMainOBBPath(expPath);
             string patchPath = GooglePlayDownloader.GetPatchOBBPath(expPath);
             
             GUI.Label(new Rect(10, 10, Screen.width-10, 20), "Main = ..."  + ( mainPath == null ? " NOT AVAILABLE" :  mainPath.Substring(expPath.Length)));
             GUI.Label(new Rect(10, 25, Screen.width-10, 20), "Patch = ..." + (patchPath == null ? " NOT AVAILABLE" : patchPath.Substring(expPath.Length)));
             if (mainPath == null || patchPath == null)
                 if (GUI.Button(new Rect(10, 100, 100, 100), "Fetch OBBs"))
                     GooglePlayDownloader.FetchOBB();
         }
         
     }
 }

I didn't attach GooglePlayDownloader to MainCamera(and I don't need to).Though I modified it, by putting my key:

 using UnityEngine;
 using System.Collections;
 using System.IO;
 using System;
 
 public class GooglePlayDownloader
 {                                                            
     private static AndroidJavaClass detectAndroidJNI;
     public static bool RunningOnAndroid()
     {
         if (detectAndroidJNI == null)
             detectAndroidJNI = new AndroidJavaClass("android.os.Build");
         return detectAndroidJNI.GetRawClass() != IntPtr.Zero;
     }
     
     private static AndroidJavaClass Environment;
     private const string Environment_MEDIA_MOUNTED = "mounted";
 
     static GooglePlayDownloader()
     {
         if (!RunningOnAndroid())
             return;
 
         Environment = new AndroidJavaClass("android.os.Environment");
         
         using (AndroidJavaClass dl_service = new AndroidJavaClass("com.unity3d.plugin.downloader.UnityDownloaderService"))
         {
         // stuff for LVL -- MODIFY FOR YOUR APPLICATION!
             dl_service.SetStatic("BASE64_PUBLIC_KEY", "my key here");
         // used by the preference obfuscater
             dl_service.SetStatic("SALT", new byte[]{1, 43, 256-12, 256-1, 54, 98, 256-100, 256-12, 43, 2, 256-8, 256-4, 9, 5, 256-106, 256-108, 256-33, 45, 256-1, 84});
         }
     }
     
     public static string GetExpansionFilePath()
     {
         populateOBBData();
 
         if (Environment.CallStatic<string>("getExternalStorageState") != Environment_MEDIA_MOUNTED)
             return null;
             
         const string obbPath = "Android/obb";
             
         using (AndroidJavaObject externalStorageDirectory = Environment.CallStatic<AndroidJavaObject>("getExternalStorageDirectory"))
         {
             string root = externalStorageDirectory.Call<string>("getPath");
             return String.Format("{0}/{1}/{2}", root, obbPath, obb_package);
         }
     }
     public static string GetMainOBBPath(string expansionFilePath)
     {
         populateOBBData();
 
         if (expansionFilePath == null)
             return null;
         string main = String.Format("{0}/main.{1}.{2}.obb", expansionFilePath, obb_version, obb_package);
         if (!File.Exists(main))
             return null;
         return main;
     }
     public static string GetPatchOBBPath(string expansionFilePath)
     {
         populateOBBData();
 
         if (expansionFilePath == null)
             return null;
         string main = String.Format("{0}/patch.{1}.{2}.obb", expansionFilePath, obb_version, obb_package);
         if (!File.Exists(main))
             return null;
         return main;
     }
     public static void FetchOBB()
     {
         using (AndroidJavaClass unity_player = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
         {
             AndroidJavaObject current_activity = unity_player.GetStatic<AndroidJavaObject>("currentActivity");
     
             AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent",
                                                             current_activity,
                                                             new AndroidJavaClass("com.unity3d.plugin.downloader.UnityDownloaderActivity"));
     
             int Intent_FLAG_ACTIVITY_NO_ANIMATION = 0x10000;
             intent.Call<AndroidJavaObject>("addFlags", Intent_FLAG_ACTIVITY_NO_ANIMATION);
             intent.Call<AndroidJavaObject>("putExtra", "unityplayer.Activity", 
                                                         current_activity.Call<AndroidJavaObject>("getClass").Call<string>("getName"));
             current_activity.Call("startActivity", intent);
     
             if (AndroidJNI.ExceptionOccurred() != System.IntPtr.Zero)
             {
                 Debug.LogError("Exception occurred while attempting to start DownloaderActivity - is the AndroidManifest.xml incorrect?");
                 AndroidJNI.ExceptionDescribe();
                 AndroidJNI.ExceptionClear();
             }
         }
     }
     
     // This code will reuse the package version from the .apk when looking for the .obb
     // Modify as appropriate
     private static string obb_package;
     private static int obb_version = 0;
     private static void populateOBBData()
     {
         if (obb_version != 0)
             return;
         using (AndroidJavaClass unity_player = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
         {
             AndroidJavaObject current_activity = unity_player.GetStatic<AndroidJavaObject>("currentActivity");
             obb_package = current_activity.Call<string>("getPackageName");
             AndroidJavaObject package_info = current_activity.Call<AndroidJavaObject>("getPackageManager").Call<AndroidJavaObject>("getPackageInfo", obb_package, 0);
             obb_version = package_info.Get<int>("versionCode");
         }
     }
 }

Here are my player settings: Bundle ID:com.firsov.jetsim Bundle version:1 Bundle version code: 1

And here's the manifest:

 <?xml version="1.0" encoding="utf-8"?>
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.unity3d.player"
     android:installLocation="preferExternal"
     android:versionCode="1"
     android:versionName="1">
     <supports-screens
         android:smallScreens="true"
         android:normalScreens="true"
         android:largeScreens="true"
         android:xlargeScreens="true"
         android:anyDensity="true"/>
 
     <application
         android:icon="@drawable/app_icon"
         android:label="@string/app_name">
         <activity android:name="com.unity3d.player.UnityPlayerProxyActivity"
                   android:label="@string/app_name"
                   android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
         <activity android:name="com.unity3d.player.UnityPlayerActivity"
                   android:label="@string/app_name"
                   android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
         </activity>
         <activity android:name="com.unity3d.player.UnityPlayerNativeActivity"
                   android:label="@string/app_name"
                   android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
             <meta-data android:name="android.app.lib_name" android:value="unity" />
             <meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="false" />
         </activity>
         <activity android:name="com.unity3d.player.VideoPlayer"
                   android:label="@string/app_name"
                   android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
         </activity>
         
 <!-- patched manifest starts here -->
         <activity android:name="com.unity3d.plugin.downloader.UnityDownloaderActivity" />
         <service android:name="com.unity3d.plugin.downloader.UnityDownloaderService" />
         <receiver android:name="com.unity3d.plugin.downloader.UnityAlarmReceiver" />
 
     </application>
     <uses-permission android:name="com.android.vending.CHECK_LICENSE" />
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 </manifest>

Anybody knows what can cause the problem? Because I've been trying to figure it out for 2 days now(. And do I need to upload the game to Google Play before testing this feature?