iOS app crashes built by Xcode 14.3: Cannot manually set the delegate on a UINavigationBar

I have an iOS app. Recently, I updated my Xcode to ver 14.3. My iOS crashed right at the start point. The following is the exception error message:

Cannot manually set the delegate on a UINavigationBar managed by a controller.

This did not happen in the previous Xcode 14.1.

I use storyboards to setup the app's UI. Here is the entrance defined in my app:

In my app info plist file, I set the entrance of the storyboard as MainStoryboard:

In this way, I don't need to specify which view controller to load as the initial start point in AppDelegate class.

The root view controller in MainStoryboard.storyboard is a tab view controller with 3 tabs, pointing to other 3 storyboard references. The root view controller is based on a customized class:

class RootViewController: UITabBarController {
    ....
}

where the three tabs are set up with titles and images. I tried to set a break point in viewLoaded event, but the crash happened before reaching my code.

I could not find any place in my iOS project where the delegate on a UINavigationBar is set manually in this storyboard or in my customized class. There is no navigation controller in the root view controller at all.

There are no any compiling warnings or errors at all. I am not sure why the exception is raised before reaching my iOS codes. Is there any property settings in my iOS project, or any settings in my MainStoryboard.storyboard that caused the error? Or are any major changes or rules in Xcode 14.3 I should comply?

The strange thing is that if I roll back to Xcode 14.1, the previous version, my app compiles and runs fine.

I greatly appreciate any help or advice to resolve the issue.

Thanks for 2 comments by neklas and Geoff-Hackworth. Following their advice, I further investigated the issue.

First, I added some codes in AppDelegate to launch my start view controller like this:

@UIApplicationMain
class AppDelegate : UIResponder, UIApplicationDelegate {

  func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?)
    -> Bool
  {
    // Set break point here
    let mainStoryboard : UIStoryboard = UIStoryboard(
        name: "MainStoryboard",
        bundle: nil)
    let initialVC : UIViewController?
      = mainStoryboard.instantiateInitialViewController()!
    // Exception raised at the above line!
    self.window = UIWindow(frame: UIScreen.main.bounds)
    self.window?.rootViewController = initialVC!
    self.window?.makeKeyAndVisible()
    
    return true
  }
}

and removed the line "Main storyboard file base name" in my app info plist file in the project. With these changes, I can let the app stop at the code in my project. As commented in the above codes, I got the same exception about "Cannot manually set the delegate on a UINavigationBar managed by a control".

I continued to chase down my other 3 storyboards. There are three navigation controllers before the start view controller in their storyboards (as linked to 3 storyboard references). In the storyboard, I did see there was a link setting between the navigation bar and navigation controller, as shown in the picture.

In the last change step, I removed this link, and the same links in another two storyboards.

That's it! After recompiling my iOS app, the app can be launched with no more errors!

I think that at the launch time of the first tab view controller, the runtime engine does check the linked tab views (all view controllers). If there is any navigation bar delegate defined, either in storyboards or codes, the new Xcode 14.3 will throw an exception error.

That's a really hard-to-find problem in my project, at least for me.

Cheers! Now I can continue to update my iOS app with the tool of Xcode 14.3. Thanks again for those two people giving me hints to find and resolve my issue.

MORE INFORMATION ABOUT MY FURTHER FINDINGS

I put the following codes in one of my view controllers to find out what has been set to the navigation bar delegate:

override func viewDidLoad()
{
    super.viewDidLoad()
    let dl = navigationController?.navigationBar.delegate
    if let dl = dl {
        print("nv: \(navigationController)\nnv bar delegate: \(dl)")
    }

The debug print result:

nv: <UINavigationController: 0x10a822600>
nv bar delegate: <UINavigationController: 0x10a822600>

It confirms that the delegate is set to the navigation controller. However, this setting cannot be repeatedly done or changed, either in the storyboard or in the code in the compiled target in Xcode 14.3.

I also did a check for the previous Xcode 14.1. Those changes do not affect my app's normal launch.