Traceback (most recent call last):
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pyforms_gui\controls\control_checkboxlist.py", line 100, in __itemSelectionChanged
    self.selection_changed_event()
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pythonvideoannotator_models_gui\dialogs\objects\objects.py", line 35, in __selection_changed_event
    def __selection_changed_event(self): self.video_selection_changed_event()
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pythonvideoannotator_models_gui\dialogs\datasets\datasets.py", line 47, in __video_selection_changed_event
    self.video_selection_changed_event()
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pythonvideoannotator_module_tracking\tracking_window.py", line 103, in __video_selection_changed_event
    self._filter.video = video
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pythonvideoannotator_module_tracking\module_mcvgui\dialogs\tracking_filter.py", line 135, in video
    self.video_capture  = value.video_capture if value is not None else None
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\mcvgui\dialogs\simple_filter\simple_filter.py", line 220, in video_capture
    self._player.value  = value
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pyforms_gui\controls\control_player\control_player.py", line 449, in value
    self.refresh()
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\pyforms_gui\controls\control_player\control_player.py", line 161, in refresh
    frame = self.process_frame_event(self._current_frame.copy())
  File "c:\users\miguel gaspar\desktop\my_virtual_environments\video_annotator\lib\site-packages\mcvgui\dialogs\simple_filter\simple_filter.py", line 142, in __process_frame
    frame_index = self._player.video_index-1
TypeError: unsupported operand type(s) for -: 'NoneType' and 'int'

OS: Microsoft Windows 10 Pro x64

Virtual Environment Python: 3.6.2

Python Video Annotator and Modules:

Python-video-annotator                                 3.306
Python-video-annotator-models                          0.8.82
Python-video-annotator-models-gui                      0.7.63
Python-video-annotator-module-background-finder        0.5.21
Python-video-annotator-module-contours-images          0.5.28
Python-video-annotator-module-create-paths             0.5.15
Python-video-annotator-module-deeplab                  0.902.21
Python-video-annotator-module-distances                0.5.18
Python-video-annotator-module-eventstats               0.5.15
Python-video-annotator-module-find-orientation         0.5.18
Python-video-annotator-module-import-export            0.5.23
Python-video-annotator-module-motion-counter           0.5.26
Python-video-annotator-module-path-editor              0.5.28
Python-video-annotator-module-path-map                 0.6.16
Python-video-annotator-module-regions-filter           0.5.18
Python-video-annotator-module-smooth-paths             0.5.19
Python-video-annotator-module-timeline                 0.6.26
Python-video-annotator-module-tracking                 0.6.38
Python-video-annotator-module-virtual-object-generator 0.6.26