PHP Laravel：如何显示视图

I'm trying to display a View having the following codes:

{!! Stored in /resources/views/about.blade.php !!}
@extends('layouts.app')
@section('title')
Conway's Game Of Life - About
@endsection

@section('content')
<h2>Conway's Game Of Life - About</h2>

<p>The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970.</p>
@endsection

Then the following main blade page:
<!-- Stored in /resources/views/layouts/app.blade.php --> <title>@yield('title')</title>
@yield('content')

After this a routes.php comes:

Route::get('/', function () {
    return view('index');
});

Route::get('/about/', function () {
     return view('about');
});

Route::get('/about/', 'HomeController@About');

I get the following errors:

`InvalidArgumentException in FileViewFinder.php line 137:

View [index.blade] not found.ErrorException in FileViewFinder.php line 137:

View [index.blade] not found. (View: C:\Bitnami\wampstack-5.5.30-0\apache2\htdocs\GameOfLifeesources\views\layouts\app.blade.php)ErrorException in FileViewFinder.php line 137:

View [index.blade] not found. (View: C:\Bitnami\wampstack-5.5.30-0\apache2\htdocs\GameOfLifeesources\views\layouts\app.blade.php) (View: C:\Bitnami\wampstack-5.5.30-0\apache2\htdocs\GameOfLifeesources\views\layouts\app.blade.php)`

What shall I do better to avoid having errors?

Thanks for helping me out of trouble!

PS, Suggestion:
Neither of the answers below find a solution to the problem. Can this be that I use PHP7, not any lesser version? It might influence the execution of Laravel program codes.

You have view called about.blade.php but you are missing view called index.blade.php which is expected since you defined that route

   Route::get('/', function () {
    return view('index');
});

Also since you are using layout templates, on top of all your views you must specify which view are you extending with @extend

https://laravel.com/docs/5.1/blade#extending-a-layout

Firs of all make sure that under layouts folder app.blade.php exists and it has these two statements @yield('content') inside body and @yield('title') between head tags.
Do one of these not both

Route::get('about', function () {
     return view('about');
});
OR
Route::get('about', 'HomeController@About');

And make sure that your index.blade.php exists under views

If you still get error please comment.