ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC1%3DCCC%28C1%28C%29C%29CCC%28C%29C%28C%29O/file?format=sdf&get3d=True  -- CC1%3DCCC%28C1%28C%29C%29CCC%28C%29C%28C%29O could not be loaded.