ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28OCCOCC%29%5CC%3DC%5Cc1ccc%28OC%29cc1/file?format=sdf&get3d=True  -- O%3DC%28OCCOCC%29%5CC%3DC%5Cc1ccc%28OC%29cc1 could not be loaded.