ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BRb%2B%5D.%5BRb%2B%5D.%5BO-%5DC%28%5BO-%5D%29%3DO/file?format=sdf&get3d=True  -- %5BRb%2B%5D.%5BRb%2B%5D.%5BO-%5DC%28%5BO-%5D%29%3DO could not be loaded.