ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1%3DCC%3DC%28C%3DC1%29C%28%3DNOCC%23N%29C%23N/file?format=sdf&get3d=True  -- C1%3DCC%3DC%28C%3DC1%29C%28%3DNOCC%23N%29C%23N could not be loaded.