ERROR opening https://cactus.nci.nih.gov/chemical/structure/CN%201%3DCC%3DCC%28%3DC1%29OC%28%3DO%29N%28C%29C/file?format=sdf&get3d=True -- CN%201%3DCC%3DCC%28%3DC1%29OC%28%3DO%29N%28C%29C could not be loaded.