Broken pipe error after calling lr finder

Dear fastai community,

I am trying to reimplement this multitask deep learning notebook for a newer version of fastai (https://medium.com/@zhang_yang/multi-task-deep-learning-experiment-using-fastai-pytorch-2b5e9d078069). Unfortunately, I am getting an error BrokenPipeError: [Errno 32] Broken pipe after calling. Please see my implementation and error: https://github.com/lubos-mobile/Multi-task/blob/master/multi-face-update.ipynb

Could anyone please help me to fix this error?

Thank you!
Best wishes,
Lubos