I made datasets according to the training on Custom Dataset tutorial. But something went wrong.`Traceback (most recent call last):


 "train.py", line 100, in <module>

for batch_i, (_, imgs, targets) in enumerate(dataloader):


 "/opt/anaconda3/envs/py36/lib/python3.6/site-packages/torch/utils/data/dataloader.py", line 637, in __next__

return self._process_next_batch(batch)


 "/opt/anaconda3/envs/py36/lib/python3.6/site-packages/torch/utils/data/dataloader.py", line 658, in _process_next_batch

raise batch.exc_type(batch.exc_msg)
TypeError: Traceback (most recent call last):

Traceback (most recent call last):


 "/home/scurest/.config/blender/2.79/scripts/addons/io_scene_gltf2/__init__.py", line 468, in execute

return self.import_gltf2(context)


 "/home/scurest/.config/blender/2.79/scripts/addons/io_scene_gltf2/__init__.py", line 487, in import_gltf2

BlenderGlTF.create(self.gltf_importer)


 "/home/scurest/.config/blender/2.79/scripts/addons/io_scene_gltf2/blender/imp/gltf2_blender_gltf.py", line 34, in create

for scene_idx, scene in enumerate(gltf.data.scenes):
TypeError: 'NoneType' object is not iterable
