ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1%3DC%28C%3DC%28C%28%3DC1Cl%29O%29Cl%29Cl/file?format=sdf&get3d=True  -- C1%3DC%28C%3DC%28C%28%3DC1Cl%29O%29Cl%29Cl could not be loaded.