ERROR opening https://cactus.nci.nih.gov/chemical/structure/%5BN%40H%5D%3DC%28N%29N2Cc1c%28cccc1%29CC2/file?format=sdf&get3d=True  -- %5BN%40H%5D%3DC%28N%29N2Cc1c%28cccc1%29CC2 could not be loaded.