ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28OCC%29Nc1ccc%28cc1N%29NCc2ccc%28F%29cc2/file?format=sdf&get3d=True  -- O%3DC%28OCC%29Nc1ccc%28cc1N%29NCc2ccc%28F%29cc2 could not be loaded.