Unrecognized selector sent to instance.. 'NSInvalidArgumentException' for MapView delegate

Question

Swift 4/Google Maps.

The crash I get is..

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIView setDelegate:]: unrecognized selector sent to instance 0x7fa1eb50d7e0'

Yes, I know there are a lot of threads on this, but looking through them has not helped me. I have debugged enough where I have a suspect, but do not know exactly how to resolve.

Here's the git repo

Some detail.. The MapViewController has three UIViews.

• MapViewController
• Main View (default one that comes with the controller) -- Menu (sub view of Main View) -- Map (sub view of Main View)

I believe I've narrowed down the crash to the statement

self.mapView.delegate = self

Here's most of the code for the MapViewController.

import UIKit
import GoogleMaps
import FirebaseDatabase

class MapViewController: UIViewController, GMSMapViewDelegate, CLLocationManagerDelegate {
    @IBOutlet var mapView: GMSMapView!

    var locationOfInterestMarker = GMSMarker()
    var userMarker = GMSMarker()
    var locationManager = CLLocationManager()
    let zoom:Float = 15
    let locationOfInterestImage:String = "hhouseicon"
    let userMarkerImage:String = "witchicon"


    override func viewDidLoad() {
        super.viewDidLoad()
        self.getLocations()
        self.locationManager.delegate = self
        self.locationManager.requestAlwaysAuthorization()
        self.locationManager.requestWhenInUseAuthorization()
        self.locationManager.startMonitoringSignificantLocationChanges()
        /**
                The next line causes crash.  I believe I need to set the delegate to something other than self.  Set the delegate to the View named Map.  However I'm not sure about the actual code for that.
         **/
        self.mapView.delegate = self //Crashes
    }

    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        guard status == .authorizedWhenInUse else {
            return
        }
        self.locationManager.startUpdatingLocation()
        self.mapView.isMyLocationEnabled = true
        self.mapView.settings.myLocationButton = true
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        guard let location = locations.first else {
            return
        }
        self.locationManager.stopUpdatingLocation()
        self.mapView.camera = GMSCameraPosition(target: location.coordinate, zoom: 15, bearing: 0, viewingAngle: 0)
        self.placeMarker(latitude: location.coordinate.latitude, longitude: location.coordinate.longitude, marker: self.userMarker, imageName: userMarkerImage)
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?){
        if let destination = segue.destination as? LocationDetialViewController {
        destination.coordinate = locationManager.location?.coordinate
        } else {
            return
        }
    } . . .
     func mapView(_ mapView: GMSMapView, didTap marker: GMSMarker) -> Bool {
            performSegue(withIdentifier: "locationDetailSegue", sender: self)
            return false
        }

    }//MapViewController

Answer 1

I had a similar issue, but the problem was i didn't inherit the module from target