ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C4H8O4/c5-1-3(7)4(8)2-6/h1,3-4,6-8H,2H2/t3-,4 /m0/s1/file?format=sdf&get3d=True  -- InChI=1S/C4H8O4/c5-1-3(7)4(8)2-6/h1,3-4,6-8H,2H2/t3-,4 /m0/s1 could not be loaded.