Trying to save I get an error

[zdavatz]

1. I am trying save a file. That results in:

PropertyPythonObject::toString(): failed for <class 'freecad.freecad_glider.tools.glider.OGGlider'>
Traceback (most recent call last):
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/encoder.py", line 258, in iterencode
    return _iterencode(o, 0)
           ^^^^^^^^^^^^^^^^^
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
<class 'TypeError'>: Object of type FeaturePython is not JSON serializable
PropertyPythonObject::toString(): failed for <class 'freecad.freecad_glider.tools.glider.OGGliderVP'>
Traceback (most recent call last):
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/encoder.py", line 258, in iterencode
    return _iterencode(o, 0)
           ^^^^^^^^^^^^^^^^^
  File "/Users/zdavatz/miniconda3/envs/openglider/lib/python3.11/json/encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
<class 'TypeError'>: Object of type ViewProviderDocumentObject is not JSON serializable