I have a working code in non-module structure.
-application
- controllers
- IndexController.php
- AuthController.php
- views
- ...

I try to separate into module sturcture
- application
- modules
- default
- controllers
- IndexController.php
- AuthController.php
- admin
- controllers
- ....


so I update the code
$frontController->setControllerDirectory('./application/controllers')

to
$frontController->setControllerDirectory(array('default' => realpath('./application/modeles/controllers/default'),
'admin' => realpath('./application/modeles/controllers/admin')
))



but I got the following error message

Fatal error: Uncaught exception 'Zend_Controller_Dispatcher_Exception' with message 'Invalid controller specified (auth)' in D:\www\dev-zend\dev\library\Zend\Controller\Dispatcher\Standa rd.php:194 Stack trace: #0 D:\www\dev-zend\dev\library\Zend\Controller\Front.php(920): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #1 D:\www\dev-zend\dev\index.php(54): Zend_Controller_Front->dispatch() #2 {main} thrown in D:\www\dev-zend\dev\library\Zend\Controller\Dispatcher\Standa rd.php on line 194


I thought I dont have to add Namespace in default, correct, what else did I miss ?
please advice.

Thanks

You'll have to change the name of your controllers. If you have a module called "users", the name of your origin AuthController will be "Users_AuthController"... so you have to prepend the module name followed by an underscore (except for your "default" module!)