Problema ao importar train_test_split

aparece a seguinte mensagem de erro:

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-58-dacacee6736c> in <module>
      1 import numpy as np
----> 2 from sklearn.model_selection import train_test_split

C:\ProgramData\Anaconda3\lib\site-packages\sklearn\__init__.py in <module>
     81     from . import __check_build  # noqa: F401
     82     from .base import clone
---> 83     from .utils._show_versions import show_versions
     84 
     85     __all__ = ['calibration', 'cluster', 'covariance', 'cross_decomposition',

C:\ProgramData\Anaconda3\lib\site-packages\sklearn\utils\_show_versions.py in <module>
     10 import importlib
     11 
---> 12 from ._openmp_helpers import _openmp_parallelism_enabled
     13 
     14 

ImportError: DLL load failed: %1 não é um aplicativo Win32 válido.