Crashing on callDelegateWithNewMessage

[heatherSnepenger]

I have been trying to implement MTStatusBarOverlay into my project. I have the status bar messages in several view controllers, and when I start clicking rapidly between view controllers, I end up getting an error in this method:

• (void)callDelegateWithNewMessage:(NSString *)newMessage {

  if ([self.delegate respondsToSelector:@selector(statusBarOverlayDidSwitchFromOldMessage:toNewMessage:)]) {
  NSString *oldMessage = nil;

  if (self.messageHistory.count > 0) {
      oldMessage = [self.messageHistory lastObject];
  }
  
  [self.delegate statusBarOverlayDidSwitchFromOldMessage:oldMessage
                                            toNewMessage:newMessage];
  

  }
  }

at the first if statement. Any thoughts? Do you need more info?