Yii generates error "Unable to resolve the request <controller/action>"

I have had a similar problem and got it solved. In this case the file was correctly named but the class name was wrongly spelled. When these two do not correspond, you could get this error too.

It is because of wrong controller file name given or may be actionIndex() method is not in your controller.

Make sure the filename of your controller is EXACTLY "MembersdetController.php". It is case sensitive.

I guess you were developing on local machine under Windows OS and server runs on *nix system. That's normal issue for novice developers, that they forget about case sensitive file system in *nix.

Check case sensitive exactly your controller: MembersdetController

Check alias (common in config/main.php) map with namespace in your controller

Yii::setAlias('@tienn2t', dirname(dirname(__DIR__)) . '/tienn2t');

In MembersdetController.php file

<?php
namespace tienn2t\controllers;

use Yii;
use yii\web\Controller;

class MembersdetController extends Controller{
    public function actionIndex(){
        echo 1;die;
    }
}