ModuleNotFoundError: No module named 'cPickle'

This error occurs because the module 'cPickle' has been removed in Python 3.x. Instead, the module 'pickle' should be used.

To fix this error, replace 'cPickle' with 'pickle' in your code. For example:

import pickle

# instead of:
# import cPickle

# usage:
my_data = {'name': 'John', 'age': 30}
serialized_data = pickle.dumps(my_data)

Note that the 'pickle' module provides the same functionality as 'cPickle', but may be slightly slower due to the lack of C implementation.