it’s probably because of this: https://github.com/pytorch/pytorch/blob/master/torch/nn/quantized/modules/linear.py#L60 16
what version of pytorch are you using? if you update to nightly the problem should be gone since we changed the serialization format for linear: https://github.com/pytorch/pytorch/blob/master/torch/nn/quantized/modules/linear.py#L220 10