ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1CN%202%3DCC%3DCC%3DC2C3%3DCC%3DCC%3DN%2031/file?format=sdf&get3d=True  -- C1CN%202%3DCC%3DCC%3DC2C3%3DCC%3DCC%3DN%2031 could not be loaded.