Laravel Can't Resend Verification Email Call to a member function hasVerifiedEmail() on null

I want to resend verification email. But I got an error Call to a member function hasVerifiedEmail() on null.

RegisterController.php

protected function registered(Request $request)
    {
        $this->guard()->logout();
        $msg = 'We sent you an activation code. Check your email and click on the link to verify. If you did not receive the email, <a href=" ' .route('verification.resend'). ' ">click here</a> to request another';
        $request->session()->flash('success',  $msg);
        return redirect('/register');
    }

VerificationController

public function __construct()
    {
        //$this->middleware('auth');
        /*$this->middleware(function($request, Closure $next) {
            if(auth()->check()) 
            {
                return $next($request);
            }

            return redirect()->route('register')->with('success', "Link verivication has been sent!");
        });*/
        $this->middleware('signed')->only('verify');
        $this->middleware('throttle:6,1')->only('verify', 'resend');
    }

Web.php

Route::get('/user/verify/{token}', 'Auth\RegisterController@verifyUser');
//Route::get('register/confirm/resend','Auth\RegisterController@resendVerification');
Route::get('email/resend', 'Auth\VerificationController@resend')->name('verification.resend');

via Chebli Mohamed