ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%5C1%3DC/C%3DC%5CC%3DC%5CC%3DC/C%3DC%5CC%3DC1/file?format=sdf&get3d=True -- C%5C1%3DC/C%3DC%5CC%3DC%5CC%3DC/C%3DC%5CC%3DC1 could not be loaded.