Get error from maml_train.py

[688spiderbin]

Hello, I get this error when I run though maml_train.py.
When I try to test
valid_task_iterable = fsmol_dataset.get_task_reading_iterable(DataFold.VALIDATION)
task = next(iter(valid_task_iterable))

It comes:

Could you tell me how to fix it ?
I appreciate a lot !