As I mentioned in the title, I want to add Navigation Controller to my application which already has a Tab Controller. So trying to do the staff so
Try to remove navigation controller from xib, so it only have view controller, then initialize navigation controller programatically:
UIViewController *tmpViewController1 = [[[YourViewController alloc] init] initWithNibName:@"YourViewController" bundle:nil];
UINavigationController *viewController1 = [[UINavigationController alloc] initWithRootViewController:tmpViewController1];