AttributeError: 'NoneType' object has no attribute 'data'

[ren01140201]

Error message: p.grad.data.mul_(1.0 / meta_batch_size)
AttributeError: 'NoneType' object has no attribute 'data'

For lines;
# Average the accumulated gradients and optimize
for p in maml.parameters():
print(p)
p.grad.data.mul_(1.0 / meta_batch_size)
opt.step()

I encountered the error message in #387 and did as recommended, added the parameter allow_unused=True.

Would it be wrong if I changed the aforementioned lines to:
with torch.no_grad():
for p in maml.parameters():
if p.grad is not None:
p.grad.data.mul_(1.0 / meta_batch_size)
opt.step()