ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC2C%28%5Cc1ccccc1N2%29%3DC/c3c%28cc%28%5BnH%5D3%29C%29C/file?format=sdf&get3d=True  -- O%3DC2C%28%5Cc1ccccc1N2%29%3DC/c3c%28cc%28%5BnH%5D3%29C%29C could not be loaded.