ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C5H6N2O/c1-5(8)7-3-2-6-4-7/h2-4H,1H3/file?format=sdf&get3d=True  -- InChI=1S/C5H6N2O/c1-5(8)7-3-2-6-4-7/h2-4H,1H3 could not be loaded.