ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C4H8O4/c5-1-3(7)4(8)2-6/h3,5-7H,1-2H2/file?format=sdf&get3d=True  -- InChI=1S/C4H8O4/c5-1-3(7)4(8)2-6/h3,5-7H,1-2H2 could not be loaded.