TypeError: a bytes-like object is required, not 'numpy.str_'`

Hey! I tried to run the code exactly how you did! I followed the steps and installed every library I have now ended up with this type cast error:
`INFO: use random key COCO_train2014_000000321310-08-T0-X740139
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
in
1 for k in range(10) :
----> 2 rgb, gt, trans_mat = dataset.get_one_sample()
3 pred = simple_cmfd_decoder( busterNetModel, rgb )
4 visualize_result( rgb, gt, pred )

~\Desktop\BusterNet-master\Data\USCISI-CMFD-Small\api.py in get_one_sample(self, key)
152 sample = tuple of (image, cmd_mask, trans_mat)
153 '''
--> 154 return self.get_samples([key])[0]
155 def get_samples( self, key_list ) :
156 '''Get samples according to a given key list

~\Desktop\BusterNet-master\Data\USCISI-CMFD-Small\api.py in get_samples(self, key_list)
172 key = np.random.choice(self.sample_keys, 1)[0]
173 print("INFO: use random key", key)
--> 174 lut_str = txn.get(key)
175 sample = self._decode_lut_str( lut_str )
176 sample_list.append(sample)

TypeError: a bytes-like object is required, not 'numpy.str_'`

The current version I am using is python 3.6.8