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