Sorry the code is complex and i couldn’t give you a code snippet. You can get the rar file from this https://drive.google.com/file/d/1biA7CJnPibJAKS7Liw60JPuKFqpV9il8/view?usp=sharing 2,  just run the train.py and may be you can get this error.
i use windows 10 and pytorch 1.4.0. Thank you so much.