ERROR opening https://cactus.nci.nih.gov/chemical/structure/CN%28C%29N%3DNc1%5BnH%5Dcnc1C%28N%29%3DO/file?format=sdf&get3d=True -- CN%28C%29N%3DNc1%5BnH%5Dcnc1C%28N%29%3DO could not be loaded.