ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C4H6O2.C2H4/c1-2-3-4(5)6;1-2/h2H,1,3H2,(H,5,6);1-2H2/file?format=sdf&get3d=True -- InChI=1S/C4H6O2.C2H4/c1-2-3-4(5)6;1-2/h2H,1,3H2,(H,5,6);1-2H2 could not be loaded.