load the .pkl file error

[JiangYan0409]

First of all, thank you very much for your great work. When I load the .pkl file【test.py 121: torch.load(checkpoint_file)】, an error occurred "_pickle.UnpicklingError: A load persistent id instruction was encountered, but no persistent_load function was specified."
If you have time, I hope to solve this problem, thank you！