ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%26%2361%3B1S/C4H6O4/c5-3%286%291-2-4%287%298/h1-2H2%2C%28H%2C5%2C6%29%28H%2C7%2C8%29/file?format=sdf&get3d=True -- InChI%3DInChI%26%2361%3B1S/C4H6O4/c5-3%286%291-2-4%287%298/h1-2H2%2C%28H%2C5%2C6%29%28H%2C7%2C8%29 could not be loaded.