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