ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCN1CCC%3DC%28C1%29C2%3DCC%28%3DNO2%29C3%3DCC%3DC%28C%3DC3%29C/file?format=sdf&get3d=True  -- CCCN1CCC%3DC%28C1%29C2%3DCC%28%3DNO2%29C3%3DCC%3DC%28C%3DC3%29C could not be loaded.