Revmob integration does not work

Hey guys, I am using the following code to integrate Revmob in my project which is attached to my Main Camera:

 #pragma strict
 
 import System.Collections.Generic;
 
 private var APP_IDS = new Dictionary.<String, String>();
 APP_IDS["Android"] = "#########"; // My media ID from revmob is put here
 private var revmob:RevMob;
 
 function Awake() {
     revmob = RevMob.Start(APP_IDS, this.gameObject.name);
     Debug.Log(this.gameObject.name);
 }
 
 function Start () {
      revmob.ShowFullscreen();
      
 }
 

When I launch the app, I see the following error message in the console:

"NullReferenceException: Object reference not set to an instance of an object AdsJavscript.Start () (at Assets/AdsJavscript.js:17) "

And if I start the app on a device, no ads are being displayed. Do you have any idea what the problem could be?