ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%26%2361%3B1S/C6H8N2/c7-8-6-4-2-1-3-5-6/h1-5%2C8H%2C7H2/file?format=sdf&get3d=True -- InChI%3DInChI%26%2361%3B1S/C6H8N2/c7-8-6-4-2-1-3-5-6/h1-5%2C8H%2C7H2 could not be loaded.