Missing controller

You are seeing this error because controller LANGController could not be found.

Notice: this error is being rendered by the app/views/errors/missing_controller.thtml view file, a user-customizable error page for handling invalid controller dispatches.

Fatal: Unable to load controller LANGController

Fatal: Create Class:

class LANGController extends AppController
    var $name = 'LANG';

in file : app/controllers/l_a_n_g_controller.php