Could you check again, that the forward pass runs successfully:
x = torch.randn( YOUR_SIZE )
output = model(x)
torch.save(model.state_dict(), filename)
model = train.Net()
model.load_state_dict(torch.load(filename))
output = model(x)
old_model = nn.Sequential(...)
x = x.to('cuda')
output = old_model(x)