ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%3DCCC1%3DCC%28OC%29%3DC%28OC%29C%28OC%29%3DC1/file?format=sdf&get3d=True  -- C%3DCCC1%3DCC%28OC%29%3DC%28OC%29C%28OC%29%3DC1 could not be loaded.