ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%3DCC1%3DCC%28%3DC%28C%3DC1OC%29OC%29OC/file?format=sdf&get3d=True  -- CC%3DCC1%3DCC%28%3DC%28C%3DC1OC%29OC%29OC could not be loaded.