ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCN%28CC%29C%28%3DO%29C1%3DCN%3DCC%3DC1/file?format=sdf&get3d=True  -- CCN%28CC%29C%28%3DO%29C1%3DCN%3DCC%3DC1 could not be loaded.