TypeError: function takes exactly 5 arguments (1 given)

when i train my dataset, i got this error

Traceback (most recent call last):
  File "train_net.py", line 192, in <module>
    main()
  File "train_net.py", line 185, in main
    model = train(cfg, args.local_rank, args.distributed)
  File "train_net.py", line 86, in train
    arguments,
  File "/root/maskrcnn-benchmark-sync/tools/../maskrcnn_benchmark/engine/trainer.py", line 68, in do_train
    for iteration, (images, targets, _) in enumerate(data_loader, start_iter):
  File "/usr/local/lib/python3.6/dist-packages/torch/utils/data/dataloader.py", line 623, in __next__
    return self._process_next_batch(batch)
  File "/usr/local/lib/python3.6/dist-packages/torch/utils/data/dataloader.py", line 658, in _process_next_batch
    raise batch.exc_type(batch.exc_msg)
TypeError: function takes exactly 5 arguments (1 given)

i think there is some error in dataset, i have checked my dataset , for example label,box valid…, but nothing help. so i trace the code to find the reason, i trace here, line 137 at dataloader.py

try:
                samples = collate_fn([dataset[i] for i in batch_indices])
            except Exception:
                # It is important that we don't store exc_info in a variable,
                # see NOTE [ Python Traceback Reference Cycle Problem ]
                data_queue.put((idx, ExceptionWrapper(sys.exc_info())))
            else:
                data_queue.put((idx, samples))
                del samples

i think problem is in BatchCollator, but i can not find any function need 5 arguments. one more thing, i train with batchsize 1 on one gpu look fine.

[kakaluote]

solved. set num_workers to 0, useful information appeared. PIL image read crashed by non ascii char, some image filename has bad string encode.

[mattpopovich]

solved. set num_workers to 0, useful information appeared. PIL image read crashed by non ascii char, some image filename has bad string encode.

Thank you, this helped for me as well. My issue was I was wrongly trying to load a .txt file (label) as an image during training.