TypeError: 'NoneType' object is not subscriptable

[Sivaaaa]

Traceback (most recent call last):
File "run_exp.py", line 68, in
algo.train()
File "C:\stageI\trainer.py", line 306, in train
counter = self.build_model(sess)
File "C:\stageI\trainer.py", line 280, in build_model
self.init_opt()
File "C:\stageI\trainer.py", line 97, in init_opt
c, kl_loss = self.sample_encoded_context(self.embeddings)
File "C:\stageI\trainer.py", line 76, in sample_encoded_context
c_mean_logsigma = self.model.generate_condition(embeddings)
File "C:\stageI\model.py", line 47, in generate_condition
custom_fully_connected(self.ef_dim * 2).
File "C:\Users\HP\Anaconda3\lib\site-packages\prettytensor\pretty_tensor_class.py", line 1973, in method
return input_layer._method_complete(result)
File "C:\Users\HP\Anaconda3\lib\site-packages\prettytensor\pretty_tensor_class.py", line 691, in _method_complete
return self.with_tensor(result)
File "C:\Users\HP\Anaconda3\lib\site-packages\prettytensor\pretty_tensor_class.py", line 978, in with_tensor
layer = Layer(copy=self, tensor=unwrap(tensor), sequence=None)
File "C:\Users\HP\Anaconda3\lib\site-packages\prettytensor\pretty_tensor_class.py", line 931, in init
self._name = self._sequence[0].op.name
TypeError: 'NoneType' object is not subscriptable