ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28C%29%28C%29c1c%28O%29c%28C%29cc%28C%29c1/file?format=sdf&get3d=True  -- CC%28C%29%28C%29c1c%28O%29c%28C%29cc%28C%29c1 could not be loaded.