Traceback (most recent call last):
  File "process.py", line 73, in <module>
    eval('../amazon/densenet169_new',128,256,2)
  File "/home/zhenghuabin/jianglibin/amazon/eval.py", line 49, in eval
    for step, (data, target) in enumerate(validate_loader):
  File "/home/zhenghuabin/anaconda3/envs/py35/lib/python3.5/site-packages/torch/utils/data/dataloader.py", line 206, in __next__
    idx, batch = self.data_queue.get()
  File "/home/zhenghuabin/anaconda3/envs/py35/lib/python3.5/multiprocessing/queues.py", line 345, in get
    return ForkingPickler.loads(res)
  File "/home/zhenghuabin/anaconda3/envs/py35/lib/python3.5/site-packages/torch/multiprocessing/reductions.py", line 70, in rebuild_storage_fd
    fd = df.detach()
  File "/home/zhenghuabin/anaconda3/envs/py35/lib/python3.5/multiprocessing/resource_sharer.py", line 58, in detach
    return reduction.recv_handle(conn)
  File "/home/zhenghuabin/anaconda3/envs/py35/lib/python3.5/multiprocessing/reduction.py", line 181, in recv_handle
    return recvfds(s, 1)[0]
  File "/home/zhenghuabin/anaconda3/envs/py35/lib/python3.5/multiprocessing/reduction.py", line 160, in recvfds
    len(ancdata))
RuntimeError: received 0 items of ancdata

Here is my code:
dset_validate = AmazonDateset_validate(validate_index)
validate_loader = DataLoader(dset_validate, batch_size=batch_size, num_workers=4)
for step, (data, target) in enumerate(validate_loader):

It always get error in the same position(finish some particular epoch). How to solve it?