ERROR opening https://cactus.nci.nih.gov/chemical/structure/c12c%28c%28ccc%28c1%29C%28C%29C%29C%29ccc2C/file?format=sdf&get3d=True  -- c12c%28c%28ccc%28c1%29C%28C%29C%29C%29ccc2C could not be loaded.