ERROR opening https://cactus.nci.nih.gov/chemical/structure/OC%28C%28O%29C%28%5BO-%5D%29%3DO%29C%28O%29%3DO/file?format=sdf&get3d=True  -- OC%28C%28O%29C%28%5BO-%5D%29%3DO%29C%28O%29%3DO could not be loaded.