ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C2H4N2O3/c3-1(5)4-2(6)7/h(H,6,7)(H3,3,4,5)/file?format=sdf&get3d=True  -- InChI=1S/C2H4N2O3/c3-1(5)4-2(6)7/h(H,6,7)(H3,3,4,5) could not be loaded.