training problem

[aijianiula0601]

  File "/data1/hjh/pycharm_projects/tts/parallel-tacotron2_try/model/parallel_tacotron2.py", line 68, in forward
    self.learned_upsampling(durations, V, src_lens, src_masks, max_src_len)
  File "/home/huangjiahong.dracu/miniconda2/envs/parallel_tc2/lib/python3.6/site-packages/torch/nn/modules/module.py", line 727, in _call_impl
    result = self.forward(*input, **kwargs)
  File "/data1/hjh/pycharm_projects/tts/parallel-tacotron2_try/model/modules.py", line 335, in forward
    mel_mask = get_mask_from_lengths(mel_len, max_mel_len)
  File "/data1/hjh/pycharm_projects/tts/parallel-tacotron2_try/utils/tools.py", line 87, in get_mask_from_lengths
    ids = torch.arange(0, max_len).unsqueeze(0).expand(batch_size, -1).to(device)
RuntimeError: upper bound and larger bound inconsistent with step sign

Thank you for you jobs. I got above problem when training. I guess it's a Duration prediction problem. How to solve it?