MethodNotAllowedHttpException in RouteCollection.php line 219

When I storing a post I get this error

MethodNotAllowedHttpException in RouteCollection.php line 219:

What can cause this problem ??

Routes.php:

Route::get('home', 'PostsController@index');
Route::get('/', 'PostsController@index');
Route::get('index', 'PostsController@index');

Route::get('posts', 'PostsController@index');
Route::get('post/{slug}/{id}', 'PostsController@show');
Route::get('posts/sukurti-nauja-straipsni', 'PostsController@create');
Route::patch('posts/store-new-post', 'PostsController@store');
Route::get('post/{slug}/{id}/edit', 'PostsController@edit');
Route::patch('posts/{slug}', 'PostsController@update');


Route::get('tags/{tags}', 'TagsController@show');
Route::get('categories/{categories}', 'CategoriesController@show');

// Authentication routes...
Route::get('auth/login', 'Auth\AuthController@getLogin');
Route::post('auth/login', 'Auth\AuthController@postLogin');
Route::get('auth/logout', 'Auth\AuthController@getLogout');

// Registration routes...
Route::get('auth/register', 'Auth\AuthController@getRegister');
Route::post('auth/register', 'Auth\AuthController@postRegister');

I'm using Laravel 5.1 and I can't figure this out for a day..

via Chebli Mohamed