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?

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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.