I can open and run the test_cavity now. However, when I close pyptv I got this message:
Traceback (most recent call last):
File "C:\Users\chris\anaconda3\envs\openptv3\lib\site-packages\enable\qt4\base_window.py", line 289, in sizeHint
return self.handler.sizeHint(qt_size_hint)
File "C:\Users\chris\anaconda3\envs\openptv3\lib\site-packages\enable\qt4\base_window.py", line 186, in sizeHint
preferred_size = self._enable_window.component.get_preferred_size()
AttributeError: 'NoneType' object has no attribute 'get_preferred_size'