title: CakePHP 3 Plugin development controller could not be found error
body: <p>I am trying to create an admin plugin for my website. I baked plugin then user model and controller but when I visit /admin/users/ or /admin/users/index it always gives an error as below:</p>
  <blockquote>
  <p>Error: Admin.UsersController could not be found.</p>
  <p>Error: Create the class UsersController below in file: C:\xampp\htdocs\cake3\plugins\Admin\src\Controller\UsersController.php</p>
  </blockquote>
  <p>But of course I have the files in correct locations. Any ideas what causes this problem?</p>
  <p>Thanks a lot for helps or even efforts.</p>
  <p>Please ask any further info</p>