ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DCC1%3DCC%28OC%29%3DC%28O%29C%3DC1/file?format=sdf&get3d=True  -- O%3DCC1%3DCC%28OC%29%3DC%28O%29C%3DC1 could not be loaded.