ERROR opening https://cactus.nci.nih.gov/chemical/structure/CNC1CCC2%3DC%28C1%29C%3DCC%28%3DC2O%29O/file?format=sdf&get3d=True  -- CNC1CCC2%3DC%28C1%29C%3DCC%28%3DC2O%29O could not be loaded.