WKWebViewのデリゲート設定でクラッシュ

#import <UIKit/UIKit.h>
#import <WebKit/WebKit.h>
#import "MBProgressHUD.h"

@interface HoneyShopViewController : UIViewController<WKNavigationDelegate>
{
    IBOutlet    WKWebView          *webView;
}
@property (strong, nonatomic) MBProgressHUD     *hud;

#import "ViewController.h"
#import <WebKit/WebKit.h>
@import GoogleMobileAds;

@interface ViewController ()
@property (weak, nonatomic) IBOutlet GADBannerView *bannerView;
@end

@implementation ViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.view.backgroundColor   = BODY_COLOR;

    webView.navigationDelegate = self;

    [webView.layer setBorderColor:LOG_COLOR.CGColor];
    [webView.layer setBorderWidth:2.0f];

    // Do any additional setup after loading the view from its nib.
    PBAppDelegate *appDelegate = (PBAppDelegate *)[UIApplication sharedApplication].delegate;
    _hud = [[MBProgressHUD alloc]initWithWindow:appDelegate.window];
    [appDelegate.window addSubview:_hud];

    // In this case, we instantiate the banner with desired ad size.
    self.bannerView = [[GADBannerView alloc]
        initWithAdSize:kGADAdSizeBanner];

    self.bannerView.adUnitID = @"ca-app-pub-3940256099942544/2934735716";
    //self.bannerView.adUnitID = @"ca-app-pub-4057658985177158~5712178529";
    self.bannerView.rootViewController = self;
    GADRequest *request = [GADRequest request];
    [self.bannerView loadRequest:request];
    [self addBannerViewToView:self.bannerView];
}

- (void)addBannerViewToView:(UIView *)bannerView {
  bannerView.translatesAutoresizingMaskIntoConstraints = NO;
  [self.view addSubview:bannerView];
  [self.view addConstraints:@[
    [NSLayoutConstraint constraintWithItem:bannerView
                               attribute:NSLayoutAttributeBottom
                               relatedBy:NSLayoutRelationEqual
                                  toItem:self.bottomLayoutGuide
                               attribute:NSLayoutAttributeTop
                              multiplier:1
                                constant:0],
    [NSLayoutConstraint constraintWithItem:bannerView
                               attribute:NSLayoutAttributeCenterX
                               relatedBy:NSLayoutRelationEqual
                                  toItem:self.view
                               attribute:NSLayoutAttributeCenterX
                              multiplier:1
                                constant:0]
                                ]];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    self.title = @"タイトル";
    self.hidesBottomBarWhenPushed = NO;
    PBDataManager   *manager    = [[[PBDataManager alloc]init]autorelease];
    NSDictionary    *user       = [manager getUserData];

    NSString        *urlStr     = HONEY_SHOP_URL;
    NSString        *uid        = [user valueForKey:@"uid"];
    NSString        *platform   = @"ios";
    NSString        *version    = [NSString stringWithFormat:@"%@",[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"]];

    [_hud show:YES];
    NSDictionary    *postParams     = [[NSDictionary alloc] initWithObjectsAndKeys:uid, @"uid",
                                       [manager getToken],@"token",
                                       platform, @"platform",
                                       version, @"version",
                                       nil];

    AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:urlStr]];
    [httpClient setDefaultHeader:@"x-appid" value:@"hogehoge"];
    NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST"
                                                            path:urlStr
                                                      parameters:postParams];
    AFHTTPRequestOperation *operation   = [[AFHTTPRequestOperation alloc] initWithRequest:request];
    [httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];
    [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSDictionary    *dict =(NSDictionary *)[[[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding]JSONValue];
        [webView loadHTMLString:[dict objectForKey:@"message"] baseURL:[[NSBundle mainBundle] pathForResource:@"html_template" ofType:@"html"]];
    }failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Shop Error: %@", error);
        [_hud hide:YES];
    }];

    [operation start];
}

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler
{
    if ([navigationAction.request.URL.scheme isEqualToString:@"inapp"]) {
        if ([[PBStoreManager sharedInstance] canMakePayment]) {
            [_hud show:YES];
        }
        decisionHandler(WKNavigationActionPolicyCancel);
        return;
    }
    decisionHandler(WKNavigationActionPolicyAllow);
}
- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(nonnull NSURLAuthenticationChallenge *)challenge completionHandler:(nonnull void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential * _Nullable))completionHandler {
    if([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodHTTPBasic] == YES){ 
        NSLog(@"didReceiveAuthenticationChallenge");
    }else{
        completionHandler(NSURLSessionAuthChallengeRejectProtectionSpace, nil);
    }
}
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation
{
    [_hud hide:YES];
}
- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error {
   [_hud hide:YES];
}