您好，想问我把所有的数据集放在了对应的文件夹下，运行python train那个命令后报错了，可以帮我看看是什么问题吗

[lxwkobe24]

Traceback (most recent call last):
File "train.py", line 21, in
dataloader = data.create_dataloader(opt)
File "/home/kas/CoCosNet-v2/data/init.py", line 33, in create_dataloader
instance.initialize(opt)
File "/home/kas/CoCosNet-v2/data/pix2pix_dataset.py", line 33, in initialize
self.ref_dict, self.train_test_folder = self.get_ref(opt)
TypeError: cannot unpack non-iterable NoneType object