ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC1NC%28%3DO%29NC%28C%28%3DO%29O%29C1/file?format=sdf&get3d=True  -- O%3DC1NC%28%3DO%29NC%28C%28%3DO%29O%29C1 could not be loaded.