Cannot add to mobile frontend

[iMarvinS]

I try to add my device to a page of my mobile frontend but when I try to do it I get the following error message:
error [pimatic-mobile-frontend]: Client error: null is not an object (evaluating 'd')

My configuration is the following:

    {
      "id" : "kamera-garten",
      "class": "IpCameraDevice",
      "name": "Garten",
      "filename": "cam_garten.jpg",
      "cameraUrl": "http://192.168.178.22:3751/cgi-bin/CGIStream.cgi?cmd=GetMJStream&usr=admin&pwd=passw",
      "width": 640,
      "height": 480,
      "refresh": 1000
    }