ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28O%29%5CC%3DC%5CC%28%3DO%29O.N.N/file?format=sdf&get3d=True  -- O%3DC%28O%29%5CC%3DC%5CC%28%3DO%29O.N.N could not be loaded.