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