Swift Admob issue's Thread 1: EXC_BAD_INSTRUCTION

I've been working on the following problem for a couple of days now and I'm getting a little upset with it. So I have a project file https://github.com/PCmex/lift-side-memu-in-swift-3 and I successfully initiated Cocoapod with it. I followed the whole admob tutorial and did all the required steps. When I try to test the app the build is OK, but after the app launches it crashes and gives me the following information:

Screenshot for error message: Thread 1: EXC_BAD_INSTRUCTION

The log gives me the following information: Google Mobile Ads SDK version:(GADRequest.sdkVersion()) fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)

Here is the app delegate.swift

import UIKit
import GoogleMobileAds
import Firebase

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    //Use Firebase library to configure APIs
    FirebaseApp.configure()
    GADMobileAds.configure(withApplicationID: "ca-app-pub-***")
    return true
}

func applicationWillResignActive(_ application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}

func applicationDidEnterBackground(_ application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(_ application: UIApplication) {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

func applicationWillTerminate(_ application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}


}

And this is the ViewController.swift

import UIKit
import GoogleMobileAds
import Firebase

class ViewController: UIViewController {

@IBOutlet weak var btnMenuButton: UIBarButtonItem!
@IBOutlet weak var bannerView: GADBannerView!
override func viewDidLoad() {
    super.viewDidLoad()

    // Aanroepen print functie voor de Google AdMob banner
    print("Google Mobile Ads SDK version:(GADRequest.sdkVersion())")
    bannerView.adUnitID = "ca-app-pub-***"
    bannerView.rootViewController = self
    bannerView.load(GADRequest())

    // Do any additional setup after loading the view, typically from a nib.
    if revealViewController() != nil {
        //            revealViewController().rearViewRevealWidth = 62
        btnMenuButton.target = revealViewController()
        btnMenuButton.action = #selector(SWRevealViewController.revealToggle(_:))

//            revealViewController().rightViewRevealWidth = 150
//            extraButton.target = revealViewController()
//            extraButton.action = "rightRevealToggle:"




    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}

I'm pretty sure I've been installing cocoa-pod / AdMob and all prerequisites correctly. When I do all steps in a new project everything works fine. But I'm trying to understand why it doesn't work in my current project. Hope someone could point me in the right direction, thanks in advance!

The variable bannerView is an implicitly unwrapped optional. That means that it is an optional variable type. Remember that unwrapping optionals will crash if its value is nil, so normally you would do some optional chaining like if let to test before unwrapping to prevent crashing. In your case, bannerView is nil, so your application crashed. An implicitly unwrapped optional is declared by placing a ! after its type (in your case, GADBannerView!).

I suggest you to go to the storyboard (or XIB) of your controller, select your GADBannerView and go to the connections inspector

And check if there is anything in the "Referencing Outlets" section (except for "New Referencing Outlet). If there is, break the connection by clicking the X button.

Then delete the @IBOutlet weak var bannerView line in the Controller and reconnect the GADBannerView to ViewController. If there is nothing in the section, simply delete @IBOutlet weak var bannerView and reconnect the GADBannerView to ViewController