ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCN%28CC%29CCC1%3DCNC2%3DC1C%3DC%28C%3DC2%29F/file?format=sdf&get3d=True -- CCCN%28CC%29CCC1%3DCNC2%3DC1C%3DC%28C%3DC2%29F could not be loaded.