code: def _attempt_to_raise_license_error(data_dir):
      
      if isinstance(data_dir, bytes):
          data_dir = _decode(data_dir)
      data_dir = os.path.join(data_dir, 'Data')
  
      current_date = dt.date.today().strftime('%Y%m%d')
      timestamp = dt.datetime.today().strftime('[%Y-%m-%d %H:%M:%S]')
      data_files = os.listdir(data_dir)
  
      for f in data_files:
          if f == (current_date + '.err'):
              file_name = os.path.join(data_dir, f)
              with fopen(file_name) as error_file:
                  for line in error_file:
                      if not line.startswith(timestamp):
                          continue
                      if 'Not valid license' in line:
                          raise LicenseError('Your license appears to have '
                                             'expired. Try running "pynlpir '
                                             'update".')
                      elif 'Can not open License file' in line:
                          raise LicenseError('Your license appears to be '
                                             'missing. Try running "pynlpir '
                                             'update".')
docs: Raise an error if NLPIR has detected a missing or expired license.
  
      :param str data_dir: The directory containing NLPIR's `Data` directory.
      :raises LicenseError: The NLPIR license appears to be missing or expired.