ERROR opening https://cactus.nci.nih.gov/chemical/structure/C1%3DCC%28%3DCC%3DC1C%28C%28%3DO%29O%29N%29O/file?format=sdf&get3d=True  -- C1%3DCC%28%3DCC%3DC1C%28C%28%3DO%29O%29N%29O could not be loaded.