ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC%28C%29NC1%3DNC%28%3DNC%28%3DN1%29OC%29NC%28C%29C/file?format=sdf&get3d=True -- CC%28C%29NC1%3DNC%28%3DNC%28%3DN1%29OC%29NC%28C%29C could not be loaded.