ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28O%29%5CC1%3DC%5CC%3DC/C%28N%29C1/file?format=sdf&get3d=True  -- O%3DC%28O%29%5CC1%3DC%5CC%3DC/C%28N%29C1 could not be loaded.