ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%28%23N%29N%3D%5BN%2B%5D%3D%5BN-%5D/file?format=sdf&get3d=True  -- C%28%23N%29N%3D%5BN%2B%5D%3D%5BN-%5D could not be loaded.