NotFoundHttpException in RouteCollection.php line 161: error

I get the NotFoundHttpException in RouteCollection.php line 161: but I can't find the error. I'm using Laravel 5.4.

I ran php artisan route:list command and I see the defined (named) route.

And here is the route file.

<?php

/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/

Route::get('/', 'LinkController@create');

Route::post('/create', 'LinkController@store');

Route::get('show/{id}', 'LinkController@show')->name('show');

And here is the part from the resource controller.

public function store(Request $request)
{
    $this->validate($request, [
        'url' => 'required|url'
    ]);

    // Generate string length of 6 characters
    $newHash = Str::random(6);

    // creates a $link object
    $link = new Link;

    //checks if link already exists in the database
    $link_in_db = DB::table('links')->where('url', '=', $request->url)->get();

    if($link_in_db === null){
        // sets the $link variables
        $link->url = $request->url;
        $link->hash = $newHash;

        // $link is saved in the database
        $link->save();

        // redirects to the route
        return redirect()->route('show', $link->id);
    }else{ // link is in the database
        // print_r($link_in_db); // testing purposes
        return redirect()->route('show', $link->id);
    }
}

And I highly appreciate any suggestion. If there are any other methods to redirect with data, please suggest.

Thank you!

via Isuru