Hello. I am trying to use WISP to analyze my MD simulations. But I keep getting the following error. File "C:\Python27\lib\site-packages\networkx\algorithms\shortest_paths\weighted.py", line 794, in _dijkstra_multisource for u, e in G_succ[v].items(): KeyError: 9 I have tried on both Linux and Windows system. I am using Python 27 with latest versions of numpy, scipy and networkx. I would be really grateful for any help. Regards, Amin.