ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%26%2361%3BNCCC%28N1%29C%28%26%2361%3BO%29O/file?format=sdf&get3d=True  -- CC1%26%2361%3BNCCC%28N1%29C%28%26%2361%3BO%29O could not be loaded.