The common problem here is that the currently loaded keys files does not match the current terminal type. Check under the "Communications" menu to see what Terminal Type you are set for. Then go to the "File" menu and do a "Read Keys" and select the corresponding keys file. Be sure to save defaults after this so that the proper keys will be loaded next time.
Another possible problem is that you need to remap a key or key sequence. This can be done with all Anzio products except Anzio Lite. Once a key is remapped, the key file can be used by Anzio Lite.