ERROR opening https://cactus.nci.nih.gov/chemical/structure/c3nccn3-c2nc1ccc%28Cl%29cc1n%28%3DO%29n2/file?format=sdf&get3d=True  -- c3nccn3-c2nc1ccc%28Cl%29cc1n%28%3DO%29n2 could not be loaded.