ERROR opening https://cactus.nci.nih.gov/chemical/structure/CC2CCN%28C%28%3DO%29CC%23N%29CC2N%28C%29c3ncnc1nccc13/file?format=sdf&get3d=True  -- CC2CCN%28C%28%3DO%29CC%23N%29CC2N%28C%29c3ncnc1nccc13 could not be loaded.