ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%5BC%40%40H%5D%28CC1%29C2%3DC1C%28C%29%3DCN%3DC2/file?format=sdf&get3d=True  -- C%5BC%40%40H%5D%28CC1%29C2%3DC1C%28C%29%3DCN%3DC2 could not be loaded.