Using as AssetBundle to replace first scene

Hello Unity Community!

Once again I am here for help.

After many failed attempts and research I come to you for an answer. Unfortunately, I have a legacy app developed in Unity3. (My clients dont want to upgrade to unity4 b/c it would take up too much of their resources) My game is over 50mb so I have to split the apk which I can successfully do. I'm not exactly sure what my problem is. But after I download the obb file my game runs fine. My problem occurs when I close the app and re-open it. I should note that I have a downloader scene which downloads all the other scenes as one assetbundle. So when I open the game for a second time, I try to skip the downloader scene. (Look at my Awake() method). But nothing happens, the game just sits still. So, I downloaded a logger app and I found out that I get this message: "sceneName (-1) has not been added to the build settings".

Can I edit the build settings during runtime, so I can make the first scene the menu scene and skip the downloader scene completely? And not in the editor in the actual app/apk/ipa? If so how can I achieve this?

Or

Am I not saving my assetbundle correctly? Thus causing a error b/c there is no menu scene b/c I didn't save it correclty.

I'm not exactly sure where I am going wrong here so any help would be appreciated!

Thank you!

 using UnityEngine;
 using System.Collections;
 using System.IO;
 using System;
 
 public class DownloadObbExample : MonoBehaviour {
         
     public string menuScene = "PrimaryMenu"; //TODO I MUST BE CHANGED BEFORE THE BUILD!!!!!!!
     public int versionNumber = 0;
     public GameObject ElementaryShell;
     public GameObject PrimaryShell;
     public GameObject ElementaryDownloadBtn;
     public GameObject PrimaryDownloadBtn;
     public SpriteText progressText;
     
     private string expPath;
     private string logtxt;
     private bool alreadyLogged = false;
     private bool downloadStarted;
     private float progress;
     
     void Awake() {
 #if UNITY_ANDROID
         Debug.Log("AWAKE I AM AWAKE DESTORYING SOME SHIT BEBFORE THE START ! <3 - ETB");
         if(menuScene == "PrimaryMenu") DestroyImmediate(ElementaryShell);
         else if (menuScene == "ElementaryMenu") DestroyImmediate(PrimaryShell);
         
         if(PlayerPrefs.GetInt("wasDownloaded", 0) == 0) { 
             //download the obb file
             StartDownload();
             //and re-write 0 with 1 - do that at application.loadlevel - if we got that far for sure we downloaded the obb
         } else {
             Application.LoadLevel(menuScene);
         }
 
 #elif UNITY_IPHONE || UNITY_EDITOR
         //we should never get here b/c this scene is only built when making a split apk - but just incase lets handle it
         Application.LoadLevel(menuScene);
 #endif
     }
     
     public void StartDownload() {
 #if UNITY_ANDROID
         if (!GooglePlayDownloader.RunningOnAndroid()) {
             Debug.LogError("Use GooglePlayDownloader only on Android device!");
             return;
         }
                 
         expPath = GooglePlayDownloader.GetExpansionFilePath();
         if (expPath == null) Debug.LogError("External storage is not available! ");
         
         else {
             string mainPath = GooglePlayDownloader.GetMainOBBPath(expPath);
             string patchPath = GooglePlayDownloader.GetPatchOBBPath(expPath);
             if(alreadyLogged == false) {
                 alreadyLogged = true;
                 if (mainPath != null) { Debug.Log("Attempted load level from !alreadyLogged statement"); StartCoroutine(loadLevel()); }
             }
             if (mainPath == null) {
                 //error obtaining path
                 allowForceDownload();    
             }
         }
 #endif
     }
     
     private void allowForceDownload() {
         if(menuScene == "PrimaryMenu") PrimaryDownloadBtn.SetActiveRecursively(true); 
         else if (menuScene == "ElementaryMenu") ElementaryDownloadBtn.SetActiveRecursively(true); 
     }
     
     private void forceDownlad() {
         StartCoroutine(loadLevel());
     }
 
     protected IEnumerator loadLevel() {
 #if UNITY_ANDROID        
         while(!Caching.ready) {
             Debug.Log("caching not ready... waitting");
             yield return null;
         }
         
         string mainPath;
         do {
             Debug.Log("fetching main path... waitting");
             yield return new WaitForSeconds(0.5f);
             mainPath = GooglePlayDownloader.GetMainOBBPath(expPath);
         } while(mainPath == null);
         
         string uri = "file://" + mainPath;
         using(WWW www = WWW.LoadFromCacheOrDownload(uri, versionNumber)) {
             while(!www.isDone ) {
                 progressText.Text = "0% Complete";
                 progress = (www.progress*100);
                 progress = Mathf.RoundToInt(progress);
                 progressText.Text = progress + "% Complete";
                 yield return null;
             }
             yield return www;
             if (www.error != null) throw new Exception("WWW download had an error:" + www.error);
             
             AssetBundle bundle = www.assetBundle;
             bundle.LoadAll();
             PlayerPrefs.SetInt("wasDownloaded", 1);
             Debug.Log("About to load the main menu");
             Application.LoadLevel(menuScene);
         }
         
 //        OLD METHOD OF DOWNLOADING
 //        if(downloadStarted == false) {
 //            downloadStarted = true;
 //            WWW www = WWW.LoadFromCacheOrDownload(uri , 0);
 //            while(!www.isDone ) {
 //                progressText.Text = "0% Complete";
 //                progress = (www.progress*100);
 //                progress = Mathf.RoundToInt(progress);
 //                progressText.Text = progress + "% Complete";
 //                yield return null;
 //            }
 //
 //            if (www.error != null) { Debug.LogError("Error dowloading: " + www.error); allowForceDownload(); }
 //            else {
 //                AssetBundle bundle = www.assetBundle;
 //                if(bundle == null) Debug.LogError(" Asset Bundle is null ");
 //                else {
 //                    bundle.LoadAll();
 //                    PlayerPrefs.SetInt("wasDownloaded", 1);
 //                    Application.LoadLevel(menuScene);
 //                }    
 //            }
 //        }
 #endif
         yield return 0;
     }
 }