ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C2H6N2O/c1-3-4%282%295/h1-2H3/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C2H6N2O/c1-3-4%282%295/h1-2H3 could not be loaded.