Load DataSet from File

Hello! I'm currently trying to load a dataset from Application.persistentDataPath however I can't figure out why it doesn't work.

What I tried right now: 1. Created a new project

2. Enabled vuforia in player settings

3. Added an ar camera

4. Created a new script with the following content and attached it to a empty gameobject:

public class VuforiaLoader : MonoBehaviour {
    void Start () {
        VuforiaARController.Instance.RegisterVuforiaStartedCallback(LoadDataSet);
    }

    private void LoadDataSet()
    {
        ObjectTracker objectTracer = TrackerManager.Instance.GetTracker<ObjectTracker>();

        DataSet dataSet = objectTracer.CreateDataSet();

        var path = Application.persistentDataPath + "/Vuforia/" + "Spheres.xml";
        var type = VuforiaUnity.StorageType.STORAGE_ABSOLUTE;
        Debug.Log("Loading dataset " + path);

        if (!DataSet.Exists(path, type)) {
            Debug.LogError("<color=blue>Data set doesn't exist</color>");
            return;
        } else {
            Debug.LogError("<color=orange>Data set exists</color>");
        }

        if (!dataSet.Load(path, type)) {
            Debug.LogError("Couldn't load dataset");
            return;
        }
       
        objectTracer.Stop();

        if (!objectTracer.ActivateDataSet(dataSet)) {
            Debug.LogError("Failed to activate dataset");
            return;
        }

        if (!objectTracer.Start()) {
            Debug.LogError("Failed to start tracker");
            return;
        }

    }
}

5. Created a Image Target Database with 2 Targets in it called "Spheres"

6. Put the two files to C:\Users\user\AppData\LocalLow\DefaultCompany\VuforiaTests\Vuforia    Spheres.xml     and      Spheres.dat

7. Ran the project

Result:

According to DataSet.Exists() the dataset exists, but dataSet.Load() isn't able to load the DataSet. Could somebody help?