ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C4H8N2O3/c1-4%287%299-3-5-6%282%298/h3H2%2C1-2H3/b6-5-/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C4H8N2O3/c1-4%287%299-3-5-6%282%298/h3H2%2C1-2H3/b6-5- could not be loaded.