Some questions when run gem

[Doublezore]

File "/home/doublezore/Code/Continual learning/PyCIL/models/gem.py", line 184, in update_representation
G[stpt:endpt, k].data.copy(params.grad.data.view(-1))
AttributeError: 'NoneType' object has no attribute 'data'

After investigation, I found that in the last fc layer of the model, there is no forward propagation. I would like to ask you how to solve this problem?

[LightingMc]

@Doublezore @zhoudw-zdw whats the solution? I am having the same error.