ERROR opening https://cactus.nci.nih.gov/chemical/structure/CN1C%28%3DNC%28%3DO%29N%28C1%3DO%29C2CCCCC2%29N%28C%29C/file?format=sdf&get3d=True  -- CN1C%28%3DNC%28%3DO%29N%28C1%3DO%29C2CCCCC2%29N%28C%29C could not be loaded.