ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BO-%5D%5BN%2B%5D%28%3DO%29C%3DC1NCCCS1/file?format=sdf&get3d=True -- %5BO-%5D%5BN%2B%5D%28%3DO%29C%3DC1NCCCS1 could not be loaded.