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