proper wya to destroy a Dataset on Unity

Hi everyone,

I've followed the following link for createing a dataset from an external path:

https://developer.vuforia.com/library/articles/Solution/Unity-Load-DataSet-from-SD-Card

I've successfully created and activate my dataset, now what I'm trying to do is to add a reset function which will reload the same dataset with a different setting (the use or not of extend tracking for example).

So far here what I've done:

public void DoAReset(){
		//deactive dataset
		ObjectTracker tracker = TrackerManager.Instance.GetTracker<ObjectTracker>();

		tracker.DeactivateDataSet (mDataset);


		List<string> trackableNames = new List<string> ();


		IEnumerable<TrackableBehaviour> trackableBehaviours = TrackerManager.Instance.GetStateManager ().GetTrackableBehaviours ();
		foreach (TrackableBehaviour trackableBehaviour in trackableBehaviours) {
			if (mDataset.Contains (trackableBehaviour.Trackable)) {
				trackableNames.Add (trackableBehaviour.Trackable.Name);

			}
		}

		foreach (string trackableName in trackableNames) {
			GameObject go = GameObject.Find (trackableName);
			DefaultTrackableEventHandler tra = go.GetComponent<DefaultTrackableEventHandler> ();
			tra.StopTrackableEventHandler ();

		}


		//remove dataset
		tracker.DestroyDataSet (mDataset, false);

		//reset mLoaded and mDataset
		mDataset = null;
		mLoaded = false;//reload model
}

Here is the StopTrackableEventHandler function:

public void StopTrackableEventHandler(){
			if (mTrackableBehaviour) {
				mTrackableBehaviour.UnregisterTrackableEventHandler (this);
			}
			TrackerManager.Instance.GetStateManager ().DestroyTrackableBehavioursForTrackable (mTrackableBehaviour.Trackable, true);
			Destroy (mTrackableBehaviour);
}

With the following code, I have to problem:

1- for the line "tracker.DestroyDataSet (mDataset, false);", if I set the second parameter to "true", I'll have an error saying that the Trackable cannot be destroy

2- When I load my dataset, my 2 trackable receive as ID 1 and 2, but after calling the reset function, those ID changed to 4 and 5, then 7 and 8 if call reset again. It probably means that the previous ImageTarget were not completely destroyed but how can destroy any previous ImageTarget?

Could you please tell me the proper way to completely remove a dataset?

I really thank you in advance for your help