ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28%3DO%29C1%3DC%28O%29OC%28C%29%3DCC1%3DO/file?format=sdf&get3d=True -- CC%28%3DO%29C1%3DC%28O%29OC%28C%29%3DCC1%3DO could not be loaded.