ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28Oc1cc%28C%29c%28cc1%29/N%3DC/N%28C%29C%29NC/file?format=sdf&get3d=True  -- O%3DC%28Oc1cc%28C%29c%28cc1%29/N%3DC/N%28C%29C%29NC could not be loaded.