ERROR opening https://cactus.nci.nih.gov/chemical/structure/N.N.OS%28%3DO%29%28%3DO%29%5BO-%5D.OS%28%3DO%29%28%3DO%29%5BO-%5D.%5BMg%2B2%5D/file?format=sdf&get3d=True -- N.N.OS%28%3DO%29%28%3DO%29%5BO-%5D.OS%28%3DO%29%28%3DO%29%5BO-%5D.%5BMg%2B2%5D could not be loaded.