How to make a modal register/login?

I want to implement a modal register/login using mdbootstrap but after trying many tutorials and examples I found this tutorial http://laravel.sillo.org/formulaire-modal/

When I copy and paste the code into the project(as it is in the tutorail) it throws the following error: jquery.js:8630 POST http://webpage.dev/register 500 (Internal Server Error).

I have thought that it might be an Ajax setup problem but after a google research I haven't found anything.

(Github of the project will be here)

            <!-- Collapsed Hamburger -->
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#app-navbar-collapse">
                <span class="sr-only">Toggle Navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>



            <!-- Right Side Of Navbar -->
            <ul class="nav navbar-nav navbar-right">
                <!-- Authentication Links -->
                @if (Auth::guest())
                    <li><a href="{{ url('/login') }}">Login</a></li>
                    <li><a href="#" id="register">Register</a></li>
                @else
                    <li class="dropdown">
                        <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">
                            {{ Auth::user()->name }} <span class="caret"></span>
                        </a>

                        <ul class="dropdown-menu" role="menu">
                            <li><a href="{{ url('/logout') }}"><i class="fa fa-btn fa-sign-out"></i>Logout</a></li>
                        </ul>
                    </li>
                @endif
            </ul>
        </div>
    </div>
</nav>

<div class="container">
    <div class="alert alert-success alert-dismissible hidden">
        You are now registered, you can login.
    </div>   
</div> 

@yield('content')

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
                <h4 class="modal-title" id="myModalLabel">Register</h4>
            </div>
            <div class="modal-body">

                <form id="formRegister" class="form-horizontal" role="form" method="POST" action="{{ url('register') }}">
                    <input type="hidden" name="_token" value="{{ csrf_token() }}">

                    <div class="form-group">
                        <label class="col-md-4 control-label">Name</label>
                        <div class="col-md-6">
                            <input type="text" class="form-control" name="name">
                            <small class="help-block"></small>
                        </div>
                    </div>

                    <div class="form-group">
                        <label class="col-md-4 control-label">E-Mail Address</label>
                        <div class="col-md-6">
                            <input type="email" class="form-control" name="email">
                            <small class="help-block"></small>
                        </div>
                    </div>

                    <div class="form-group">
                        <label class="col-md-4 control-label">Password</label>
                        <div class="col-md-6">
                            <input type="password" class="form-control" name="password">
                            <small class="help-block"></small>
                        </div>
                    </div>

                    <div class="form-group">
                        <label class="col-md-4 control-label">Confirm Password</label>
                        <div class="col-md-6">
                            <input type="password" class="form-control" name="password_confirmation">
                        </div>
                    </div>

                    <div class="form-group">
                        <div class="col-md-6 col-md-offset-4">
                            <button type="submit" class="btn btn-primary">
                                Register
                            </button>
                        </div>
                    </div>
                </form>                       

post in LARACASTS

<!-- JavaScripts -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script>

$(function(){

    $('#register').click(function() {
        $('#myModal').modal();
    });

    $(document).on('submit', '#formRegister', function(e) {  
        e.preventDefault();
          
        $('input+small').text('');
        $('input').parent().removeClass('has-error');
          
        $.ajax({
            method: $(this).attr('method'),
            url: $(this).attr('action'),
            data: $(this).serialize(),
            dataType: "json"
        })

        .done(function(data) {
            $('.alert-success').removeClass('hidden');
            $('#myModal').modal('hide');
        })
        .fail(function(data) {
            $.each(data.responseJSON, function (key, value) {
                var input = '#formRegister input[name=' + key + ']';
                $(input + '+small').text(value);
                $(input).parent().addClass('has-error');
            });
        });
    });

})

</script>
{{-- <script src="{{ elixir('js/app.js') }}"></script> --}}