ERROR opening https://cactus.nci.nih.gov/chemical/structure/n1%28c2c%28cccc2%29C%29c%28c2c%28cccc2%29nc1C%29%3DO/file?format=sdf&get3d=True  -- n1%28c2c%28cccc2%29C%29c%28c2c%28cccc2%29nc1C%29%3DO could not be loaded.