KlDivBackward
Hi,
I fine-tune bert and using KLDivLoss instead of CrossEntropyLoss in binary classification. when I call 
loss.backward()
I got this error !?

![error-KLDiv](https://user-images.githubusercontent.com/55197626/81508647-4dd85780-92d3-11ea-9547-a9690b733a61.PNG)


Thank you in advance
This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.
