ERROR opening https://cactus.nci.nih.gov/chemical/structure/c12c%28cccc1%29cccc2.Cl%2A.Cl%2A.Cl%2A.Cl%2A/file?format=sdf&get3d=True  -- c12c%28cccc1%29cccc2.Cl%2A.Cl%2A.Cl%2A.Cl%2A could not be loaded.