ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BN%40H%5D%3DC%28%5CN%3DC%28/N%29N%29N%28C%29C/file?format=sdf&get3d=True  -- %5BN%40H%5D%3DC%28%5CN%3DC%28/N%29N%29N%28C%29C could not be loaded.