Every connection in Interface Builder causes a SIGABRT!

I have three views that I switch between using a tab bar, and the two first views work as they should. The third view also loads and displays the images, labels, buttons, etc., I place there in IB. However, when I try to make a connection, for example between a l开发者_如何学Pythonabel declared in the third view controller, and the label in Interface Builder, I get a SIGABRT error when trying to load the view. The log shows, among other things:

Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key label.'

Can anybody help me?

Of course, UIViewController will not respond to your customized keys of your subclass. You should configure "File's Owner" to correct type of your view controller subclass in your Interface Builder.