Error when starting training

[ghost]

I've been struggling too much days with this error, maybe it's really simple but i can't figure out the reason yet. The error is the following:

Traceback (most recent call last):
File "main.py", line 205, in
main(parse_arguments(sys.argv[1:]))
File "main.py", line 169, in main
src_train_dataloader, tgt_train_dataloader, optimizer, epoch)
File "/Volumes/Elements/DANN/pytorch_DANN-master/train/train.py", line 36, in train
for batch_idx, (sdata, tdata) in enumerate(zip(source_dataloader, target_dataloader)):
File "/Volumes/Elements/Apps/anaconda3/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 615, in next
batch = self.collate_fn([self.dataset[i] for i in indices])
File "/Volumes/Elements/Apps/anaconda3/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 615, in
batch = self.collate_fn([self.dataset[i] for i in indices])
File "/Volumes/Elements/Apps/anaconda3/lib/python3.7/site-packages/torchvision/datasets/mnist.py", line 95, in getitem
img = self.transform(img)
File "/Volumes/Elements/Apps/anaconda3/lib/python3.7/site-packages/torchvision/transforms/transforms.py", line 60, in call
img = t(img)
File "/Volumes/Elements/Apps/anaconda3/lib/python3.7/site-packages/torchvision/transforms/transforms.py", line 163, in call
return F.normalize(tensor, self.mean, self.std, self.inplace)
File "/Volumes/Elements/Apps/anaconda3/lib/python3.7/site-packages/torchvision/transforms/functional.py", line 208, in normalize
tensor.sub_(mean[:, None, None]).div_(std[:, None, None])
IndexError: too many indices for tensor of dimension 0

I'd appreciate a lot your help.