trouble loading file with www on the hololens after writing during runtime

Hi guys/gals, I can't get unity to load a file that exists on the Hololens app's local persistent storage. I call the following code after I downloaded a new file and saved it to my device. Here's my code: (of course I'm starting the coroutine and passing the filename parameter)

 StartCoroutine(GetClip(fileName));

 IEnumerator GetClip(string fileName)
     {
      if (File.Exists(GetFilePath(fileName)))   
         {
             Debug.Log(fileName + " clip found in resources folder, playing that");
             return true;
             using (WWW www = new WWW("file:///" + GetFilePath(fileName)))
             {
                 yield return www;   
                 if (www.error!=null){
                     Debug.Log("www error is: " + www.error);
                     Debug.Log("www says: " + www.text);
                 }
                 else{
                     audioSource.clip = www.GetAudioClipCompressed(false, AudioType.OGGVORBIS);
                     Debug.Log("Playing clip" + fileName);
                 }
             }
 
         audioSource.Play();
         }
     }
 
 private string GetFilePath(string fileName)
     {
         Debug.Log("Returning path: " + Path.Combine(Application.persistentDataPath, fileName));
         return Path.Combine(Application.persistentDataPath, fileName);
     }

My output is:

Returning path: C:/Data/Users/andre/AppData/Local/Packages/MixedRealityToolkit-Unity_zbb2d34ez0get /LocalState\greetings%21.ogg greetings%21.ogg clip found in resources folder, playing that www error is: 404 Not Found www says: Also: I've logged onto the hololens file explorer and the file is there and I can play it on my media player, so it should work!~~