ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C6H8O2/c1-2-3-4-5-6(7)8/h2-5H,1H3,(H,7,8)/b3-2 ,5-4 /file?format=sdf&get3d=True  -- InChI=1S/C6H8O2/c1-2-3-4-5-6(7)8/h2-5H,1H3,(H,7,8)/b3-2 ,5-4  could not be loaded.