ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28O%29CC3%28OCCc2c3nc1c%28cccc12%29CC%29CC/file?format=sdf&get3d=True  -- O%3DC%28O%29CC3%28OCCc2c3nc1c%28cccc12%29CC%29CC could not be loaded.