Admin Module goes to 404 page

Question

I am new in magento and creating a module for use of both frontend and backend. Module works perfectly on frontend but it does not work in Magento Admin. It goes to 404 page.Here is the config file and IndexController file. Any help?

config.xml

<config>
<modules>
    <Mymodule_Customerpage>
        <version>1.0.0</version>
    </Mymodule_Customerpage>
</modules>
<admin>
    <routers>
        <the_name_of_this_element_is_not_important_it_should_be_unique>
            <use>admin</use>
            <args>
                <modules>
                <Mymodule_Customerpage before="Mage_Adminhtml">Mymodule_Customerpage</Mymodule_Customerpage>
                </modules>
            </args>
        </the_name_of_this_element_is_not_important_it_should_be_unique>
    </routers>
</admin>
<adminhtml>
    <menu>
        <tutorial_menu translate="title" module="mymodule_customerpage">
            <title>Artwork</title> 
            <sort_order>9999</sort_order>
            <children>
                <first_page module="mymodule_customerpage">
                    <title>Artwork</title> 
                    <action>adminhtml/mymodule_customerpage/index</action>
                </first_page>
            </children>
        </tutorial_menu>
    </menu>    
</adminhtml>
<frontend>
    <layout>
        <updates>
            <mymodule_customerpage module="mymodule_customerpage">
                <file>mymodule_customerpage.xml</file>
            </mymodule_customerpage>
        </updates>
    </layout>    
    <routers>
        <mymodule_customerpage>
            <use>standard</use>
            <args>
                <module>Mymodule_Customerpage</module>
                <frontName>mymodule_customerpage</frontName>
            </args>
        </mymodule_customerpage>
    </routers>        
</frontend>
<global>
<models>
    <mymodule_customerpage>
        <class>Mymodule_Customerpage_Model</class>
        <resourceModel>mymodule_customerpage_mysql4</resourceModel>
    </mymodule_customerpage>
    <mymodule_customerpage_mysql4>
        <class>Mymodule_Customerpage_Model_Mysql4</class>
        <entities>
            <customerpage>
                <table>customerpage</table>
            </customerpage>
        </entities>
    </mymodule_customerpage_mysql4>
</models>
<resources>
    <mymodule_customerpage_setup>
        <setup>
            <module>Mymodule_Customerpage</module>
        </setup>
        <connection>
            <use>core_setup</use>
        </connection>
    </mymodule_customerpage_setup>
    <mymodule_customerpage_write>
        <connection>
            <use>core_write</use>
        </connection>
    </mymodule_customerpage_write>
    <mymodule_customerpage_read>
        <connection>
            <use>core_read</use>
        </connection>
    </mymodule_customerpage_read>
</resources>
<helpers>
    <mymodule_customerpage>
        <class>Mymodule_Customerpage_Helper</class>
    </mymodule_customerpage>
</helpers>

Mymodule/Customerpage/Controller/Adminhtml/IndexController.php

class Mymodule_Customerpage_Adminhtml_IndexController extends Mage_Adminhtml_Controller_Action{
public function indexAction()
{
    $this->loadLayout();

     $block = $this->getLayout()
     ->createBlock('core/text', 'adminhtml_artwork')
     ->setText('<h1>This is a text block</h1>');

    $this->_addContent($block);

    $this->renderLayout();
} }

Answer 1

move your controller to Mymodule/Customerpage/Controller/Adminhtml/Customerpage/IndexController.php and rename your class to Mymodule_Customerpage_Adminhtml_Customerpage_IndexController

Answer 2

You need to Logout then login again

or

follow the steps :

Step 1: Login your Magento Admin Panel.

Step 2: Go to Systems >> Permission >> Roles >> administrators >> under role info tab >> type current admin password >> save.

then check configuration. Hope it will help.

Answer 3

On top of what Marius said, you should add the following to your controller class:

protected function _isAllowed()
{
    return Mage::getSingleton('admin/session')->isAllowed('tutorial_menu/firstpage');
}

Answer 4

I think error should be here

I change just this line

   <mymodule_customerpage before="Mage_Adminhtml">Mymodule_Customerpage_Adminhtml</mymodule_customerpage> 

see Updated code at below

<admin>
<routers>
    <the_name_of_this_element_is_not_important_it_should_be_unique>
        <use>admin</use>
        <args>
            <modules>
            <mymodule_customerpage before="Mage_Adminhtml">Mymodule_Customerpage_Adminhtml</mymodule_customerpage> <!--this node should be in small-->
            </modules>
        </args>
    </the_name_of_this_element_is_not_important_it_should_be_unique>
</routers>
</admin>