ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C2H3NO4/c1-2(4)7-3(5)6/h1H3/file?format=sdf&get3d=True  -- InChI=1S/C2H3NO4/c1-2(4)7-3(5)6/h1H3 could not be loaded.