AttributeError: 'MissingValues' object has no attribute 'to_list'

[mbobinger]

Thank you for the great tutorial, can you help me troubleshooting following error:
My setup:

• Windows 10, Pycharm IDE with a new project for this tutorial, Python3.6, freshly installed the needed packages.

The code executes the graphs well until this position:
df[LABEL] = le.fit_transform(df["activity"].values.ravel())

and throws following error:

Traceback (most recent call last):
  File "C:/Users/bobin/PycharmProjects/Mussel/cnn_musseltest.py", line 226, in <module>
    df[LABEL] = le.fit_transform(df["activity"].values.ravel())
  File "C:\Users\bobin\PycharmProjects\Mussel\venv\lib\site-packages\sklearn\preprocessing\_label.py", line 117, in fit_transform
    self.classes_, y = _unique(y, return_inverse=True)
  File "C:\Users\bobin\PycharmProjects\Mussel\venv\lib\site-packages\sklearn\utils\_encode.py", line 31, in _unique
    return _unique_python(values, return_inverse=return_inverse)
  File "C:\Users\bobin\PycharmProjects\Mussel\venv\lib\site-packages\sklearn\utils\_encode.py", line 133, in _unique_python
    uniques.extend(missing_values.to_list())
AttributeError: 'MissingValues' object has no attribute 'to_list'