Asset bundle not load the object, but it download

Hi all, I used this script for downloading my object from server and load. My download progress is working fine, but it's not showing/loading the object.

 IEnumerator Start()
     {
         WWW www = WWW.LoadFromCacheOrDownload (url, 1);
         { 
             while( !www.isDone )
             {
                 progress = " " + (www.progress * 100.0f).ToString("#") + " %";
                 yield return null;
             }
             yield return www;
             AssetBundle bundle = www.assetBundle;
             GameObject Table_Mate = bundle.Load("Table_Mate", typeof(GameObject)) as GameObject;
             
             Instantiate (Table_Mate);
         }
     }

Here is the snippet. I searched many places, but still didn't get anything, and i don't have any errors.