ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC3c1ccccc1N%28C%28%3DO%29CN2CCN%28C%29CC2%29c4ncccc4N3/file?format=sdf&get3d=True -- O%3DC3c1ccccc1N%28C%28%3DO%29CN2CCN%28C%29CC2%29c4ncccc4N3 could not be loaded.