ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCCCCC%5BC%40H%5D%28%5BC%40%40H%5D%28CC/file?format=sdf&get3d=True  -- CCCCCCC%5BC%40H%5D%28%5BC%40%40H%5D%28CC could not be loaded.