title: Attempting to load AssetReference that has already been loaded
body: <p>When I start the main scene and test a new character it shows this error why?</p>
  <pre><code>Attempting to load AssetReference that has already been loaded. Handle is exposed through getter OperationHandle
  UnityEngine.AddressableAssets.AssetReference:LoadAssetAsync&lt;UnityEngine.GameObject&gt; ()
  TrackManager/&lt;SpawnFromAssetReference&gt;d__104:MoveNext () (at Assets/Scripts/Tracks/TrackManager.cs:565)
  UnityEngine.MonoBehaviour:StartCoroutine (System.Collections.IEnumerator)
  TrackManager:SpawnObstacle (TrackSegment) (at Assets/Scripts/Tracks/TrackManager.cs:556)
  TrackManager/&lt;SpawnNewSegment&gt;d__102:MoveNext () (at Assets/Scripts/Tracks/TrackManager.cs:538)
  UnityEngine.SetupCoroutine:InvokeMoveNext (System.Collections.IEnumerator,intptr)
  </code></pre>
  <p>my code :</p>
  <pre><code>    if (m_SafeSegementLeft &lt;= 0)
      {
          SpawnObstacle(newSegment);
      }
      else
          m_SafeSegementLeft -= 1;
  
      m_Segments.Add(newSegment);
  
      if (newSegmentCreated != null) newSegmentCreated.Invoke(newSegment);
  }
  
  
  public void SpawnObstacle(TrackSegment segment)
  {
      if (segment.possibleObstacles.Length != 0)
      {
          for (int i = 0; i &lt; segment.obstaclePositions.Length; ++i)
          {
              AssetReference assetRef = segment.possibleObstacles[Random.Range(0, segment.possibleObstacles.Length)];
              StartCoroutine(SpawnFromAssetReference(assetRef, segment, i));
          }
      }
  
      StartCoroutine(SpawnCoinAndPowerup(segment));
  }
  
  private IEnumerator SpawnFromAssetReference(AssetReference reference, TrackSegment segment, int posIndex)
  {
      AsyncOperationHandle op = reference.LoadAssetAsync&lt;GameObject&gt;();
      yield return op; 
      GameObject obj = op.Result as GameObject;
      if (obj != null)
      {
          Obstacle obstacle = obj.GetComponent&lt;Obstacle&gt;();
          if (obstacle != null)
              yield return obstacle.Spawn(segment, segment.obstaclePositions[posIndex]);
      }
  }
  </code></pre>
  <p>It says i have error in line 565 which is <code>AsyncOperationHandle op = reference.LoadAssetAsync&lt;GameObject&gt;();</code></p>
  <p>What is the error here?</p>