I can't run this project sucessfully,could you help me?

[liusheng134]

File ".\train.py", line 256, in
train()
File ".\train.py", line 241, in train
loss.backward()
File "E:\anaconda\envs\tensorflow\lib\site-packages\torch\tensor.py", line 118, in backward
torch.autograd.backward(self, gradient, retain_graph, create_graph)
File "E:\anaconda\envs\tensorflow\lib\site-packages\torch\autograd_init_.py", line 93, in backward
allow_unreachable=True) # allow_unreachable flag
RuntimeError: element 0 of tensors does not require grad and does not have a grad_fn

[ReverseSystem001]

do you resolve this problem now?