As per the error description:
UIViewController is missing function
LoginButton:, and some part of your code is trying to invoke this function. Thus, crash is happening. I am not able to read the crash properly (since its not formatted well) - but, from what I can understand - its a touch event (probably on a
UIButton) that's triggering the invocation of
LoginButton: method. Since the method is not available, its crashing.
unrecognized selector sent to instance - specifically means that a function is being invoked which is not available. Also, check connection to this function from your