Extending a controller while in a sub-folder.

[eluser]InsiteFX[/eluser]
CI 1.7.x application/libraries
MY_Controller
Admin_Controller extends MY_Controller
Public_Controller extends MY_Controller

CI 2.0 application/core
MY_Controller
Admin_Controller extends MY_Controller
Public_Controller extends MY_Controller

This
/libraries/AdminController.php

This should be
/libraries/Admin_Controller.php

Then extend your application/controllers/welcome.php from Admin_Controller

InsiteFX