Unity Asset Bundles Android

I am currently trying to build an app that downloads asset bundles at runtime for mobile devices. I have got it to work on the web-player but have found issues trying to get it to work on android. I have tried adding the BuildTarget.Android and it built a different asset but when I try download it I get a 404 file not found error, I have triple checked my link and uploaded multiple files, it just seems that it does not recognise the android built asset.

 using (WWW www = WWW.LoadFromCacheOrDownload("http://luminaryserver.com/LuminAR/Luminary/android.unity3d", 0)) {
             yield return www;
             
             if (www .error != null)
                 throw new UnityException("WWW Download had an error: " + www .error);
             
             AssetBundle bundle = www.assetBundle;
 
             mBundleInstance = Instantiate(bundle.Load ("Cube")) as GameObject;

I build the assets like so:

 [MenuItem("Assets/Build AssetBundle From Selection - Track dependencies")]
     static void ExportAssetBundleComplete() {
         // Bring up save panel
         string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
         if (path.Length != 0) {
             // Build the resource file from the active selection.
             //
             Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
             //
             BuildPipeline.BuildAssetBundle(Selection.activeObject, selection, path, BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets, BuildTarget.Android);
             Selection.objects = selection;
             //
         }
     }

Thanks in advance for any help