R-50-GN.pkl can't be loaded by torch.load()

[WBS-123]

when i run follow code:

model_dict = torch.load('R-50-GN.pkl')

and report this error:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xdf in position 1: invalid continuation byte
the file is downloaded at https://dl.fbaipublicfiles.com/detectron/ImageNetPretrained/47261647/R-50-GN.pkl
how can i load this pretrained model to resnet50 in pytorch? and will you provide pytorch pretrained model of resnet50 with gn?
THX~