ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%3D1S/C4HN3/c5-1-4%282-6%293-7/h4H/file?format=sdf&get3d=True  -- InChI%3DInChI%3D1S/C4HN3/c5-1-4%282-6%293-7/h4H could not be loaded.