Hi,
I am not sure but it may be related to an issue in this thread:

  
    
    
    ERROR:optimizer got an empty parameter list 
  
  
    Do: 
G_params = list(G.parameters())
D_params = list(D.parameters())

.parameters() is a generator, and probably for debugging purposes you are pre-populating it somewhere.
  


I have no clue but apparently it works!
Bests