Laravel背包CRUD无法正常工作

我按照本教程设置了一个 CRUD 示例。但我无法让它工作，我不知道为什么。这是我的代码

SomeitemCrudController.php

<?php

namespace App\Http\Controllers\Admin;

use Backpack\CRUD\app\Http\Controllers\CrudController;

// VALIDATION: change the requests to match your own file names if you need form validation
use App\Http\Requests\SomeitemRequest as StoreRequest;
use App\Http\Requests\SomeitemRequest as UpdateRequest;

class SomeitemCrudController extends CrudController
{

    public function setUp()
    {
        /*
        |--------------------------------------------------------------------------
        | BASIC CRUD INFORMATION
        |--------------------------------------------------------------------------
        */
        $this->crud->setModel("App\Models\Someitem");
        $this->crud->setRoute("admin/someitem");
        $this->crud->setEntityNameStrings('someitem', 'someitems');

        /*
        |--------------------------------------------------------------------------
        | BASIC CRUD INFORMATION
        |--------------------------------------------------------------------------
        */

        $this->crud->setFromDb();

        // $this->crud->setColumns(['nama']);
        $this->crud->addField([
            'nama' => 'Nama',
            'keterangan' => 'Keterangan',
            'harga' => 'Harga'
        ]);
    }

    public function store(StoreRequest $request)
    {
        $redirect_location = parent::storeCrud();
        return $redirect_location;
    }

    public function update(UpdateRequest $request)
    {
        $redirect_location = parent::updateCrud();
        return $redirect_location;
    }
}

模型，Someitem.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Backpack\CRUD\CrudTrait;

class SomeItem extends Model
{
    use CrudTrait;
    //

    protected $table = 'someitem';
    protected $fillable = ['nama', 'keterangan', 'harga'];
    public $timestamps = true;
}

请求，SomeitemRequest.php

<?php

namespace App\Http\Requests;

use App\Http\Requests\Request;

class SomeitemRequest extends \Backpack\CRUD\app\Http\Requests\CrudRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return \Auth::check();
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            // 'name' => 'required|min:5|max:255'
        ];
    }

    /**
     * Get the validation attributes that apply to the request.
     *
     * @return array
     */
    public function attributes()
    {
        return [
            //
        ];
    }

    /**
     * Get the validation messages that apply to the request.
     *
     * @return array
     */
    public function messages()
    {
        return [
            //
        ];
    }
}

然后，路线

<?php

Route::group([
    'prefix' => config('backpack.base.route_prefix', 'admin'),
    'middleware' => ['admin'],
    'namespace' => 'Admin'
], function() {
    CRUD::resource('pelayanan', 'Admin\PelayananCrudController');
    Route::get('/test', function () {
        return view('welcome');
    });
});

我可以http://localhost/myapp/public/admin/test成功访问，但我无法访问http://localhost/myapp/public/admin/someitem，它总是返回错误500

我是laravel（和PHP）的新手，任何帮助表示赞赏。谢谢！