ERROR opening https://cactus.nci.nih.gov/chemical/structure/Cn1c%28N%28%3DO%29%3DO%29cnc1C%28O%29c2cc%28C%28C%29%28C%29C%29ccc2O/file?format=sdf&get3d=True -- Cn1c%28N%28%3DO%29%3DO%29cnc1C%28O%29c2cc%28C%28C%29%28C%29C%29ccc2O could not be loaded.