Getting Nan after first iteration with custom loss

[aam541 (mohammed alawad)]

@ptrblck

print(model.fc1.weight.grad)

Sure, I printed the gradient after the backward() and it shows this:
tensor([[nan, nan, nan, …, nan, nan, nan],
[nan, nan, nan, …, nan, nan, nan],
[nan, nan, nan, …, nan, nan, nan],
…,
[nan, nan, nan, …, nan, nan, nan],
[nan, nan, nan, …, nan, nan, nan],
[nan, nan, nan, …, nan, nan, nan]], device=‘cuda:0’)