ERROR opening https://cactus.nci.nih.gov/chemical/structure/Cl%26%2391%3BSn%26%2393%3B%28Cl%29%28Cl%29Cl/file?format=sdf&get3d=True  -- Cl%26%2391%3BSn%26%2393%3B%28Cl%29%28Cl%29Cl could not be loaded.