The model from which you are loading the checkpoint from and the model that you are currently using differ in certain layers as mentioned in the traceback. I just had a look at the model. Did you tweak the input to the model instantiation? I have pasted some code from the tutorial below to clarify the question.

D_G_INPUT_DIM = len(train_data.columns) --> Are you using different train data?
ids_model = Blackbox_IDS(D_G_INPUT_DIM,2) --> What is your D_G_INPUT_DIM?
param = th.load(‘save_model/IDS.pth’)
ids_model.load_state_dict(param)