ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C3H4N4O2/c4-1-5-2(8)7-3(9)6-1/h(H4,4,5,6,7,8,9)/file?format=sdf&get3d=True -- InChI=1S/C3H4N4O2/c4-1-5-2(8)7-3(9)6-1/h(H4,4,5,6,7,8,9) could not be loaded.