Routes in Laravel 5.4

I was using Laravel 5.2 and this how I was writing the named routes

Route::group( [ 'prefix' => 'admin' ], function () {
Route::resource( 'about', 'AboutController', [ 'as' => 'about' ] );
} );

and then this is how I call the route about.admin.about.update Now in Laravel 5.4 it's the same routes

Route::group( [ 'prefix' => 'admin' ], function () {
Route::resource( 'about', 'AboutController', [ 'as' => 'about' ] );
} );

but when I call it about.admin.about.update it gives route is not defined. another thing as I understood in named routes I can call the routes just like that about.admin.create

any clarification around this please

via Chebli Mohamed