ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCCCCCCCCCCCC%3DCC%28C%28COP%28%3DO%29%28O%29O%29N%29O/file?format=sdf&get3d=True  -- CCCCCCCCCCCCCC%3DCC%28C%28COP%28%3DO%29%28O%29O%29N%29O could not be loaded.