ERROR opening https://cactus.nci.nih.gov/chemical/structure/c12c%28%5BnH%5Dcn2%29ncnc1NC%5CC%3DC%28%5CCO%29C/file?format=sdf&get3d=True  -- c12c%28%5BnH%5Dcn2%29ncnc1NC%5CC%3DC%28%5CCO%29C could not be loaded.