04-08-2013 05:34 PM
Normally a keycode is sent when someone is testing something out in its beta stage. For example, I'm part of BlackBerry Beta Zone and if I want to test out the new beta version of Facebook, I'm sent a keycode via email.
If it's asking for a keycode, I would suggest perhaps you're attempting to use a beta version of BlackBerry World. Try typing www.blackberry.com/appworld in your phone's browser and see if it'll let you download the current version that is publicly available.
That's all I can think of, I hope it helps you.