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