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