ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%28CCN%28C%29C%29C%28c1ncccc1%29%28c2ccccc2%29C/file?format=sdf&get3d=True  -- O%28CCN%28C%29C%29C%28c1ncccc1%29%28c2ccccc2%29C could not be loaded.