ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C4H8N2O4/c5-2(4(8)9)1-3(7)6-10/h2,10H,1,5H2,(H,6,7)(H,8,9)/t2-/m0/s1/file?format=sdf&get3d=True  -- InChI=1S/C4H8N2O4/c5-2(4(8)9)1-3(7)6-10/h2,10H,1,5H2,(H,6,7)(H,8,9)/t2-/m0/s1 could not be loaded.