ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC2N%28CC%28%3DO%29Nc1c%28cccc1C%29C%29CCC2/file?format=sdf&get3d=True -- O%3DC2N%28CC%28%3DO%29Nc1c%28cccc1C%29C%29CCC2 could not be loaded.