ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BO-%5D%5BN%2B%5D%28%3DO%29c2c1c%28cccc1%29%5Bn%2B%5D%28%5BO-%5D%29cc2/file?format=sdf&get3d=True  -- %5BO-%5D%5BN%2B%5D%28%3DO%29c2c1c%28cccc1%29%5Bn%2B%5D%28%5BO-%5D%29cc2 could not be loaded.