404 error in Custom Magento configuration in admin

Question

I'm developing a custom SMS module in Magento 1.6.

I've setup the system.xml file to manage the related custom configuration fields.

The menu entry shows up, but when I click it, a 404 error page is shown instead of the expected configuration fields list.

Can you see any errors in my code?

<config>
<tabs>
    <mynew_tab translate="label">
        <label>SMS Gateway Integration</label>
        <sort_order>100</sort_order>
    </mynew_tab>
</tabs>
<sections>
    <smsconfig  translate="label">
        <label>SMS Gateway Integration</label>
        <sort_order>200</sort_order>
        <show_in_default>1</show_in_default>
        <show_in_website>1</show_in_website>
        <show_in_store>1</show_in_store>
        <tab>mynew_tab</tab>
        <groups>
            <sms_group translate="label">
                <label>My Custom Configurations</label>
                <comment>This is example of custom configuration.</comment>
                <sort_order>10</sort_order>
                <show_in_default>1</show_in_default>
                <show_in_website>1</show_in_website>
                <show_in_store>1</show_in_store>
                <fields>
                    <sms_enabled translate="label tooltip comment">
                        <label>Is Enabled</label>
                        <frontend_type>select</frontend_type>
                        <source_model>adminhtml/system_config_source_yesno</source_model>
                        <sort_order>0</sort_order>
                        <show_in_default>1</show_in_default>
                        <show_in_website>1</show_in_website>
                        <show_in_store>1</show_in_store>
                        <comment>Enable this module.</comment>
                    </sms_enabled>
                    <sms_username translate="label tooltip comment">
                        <label>Sender Email</label>
                        <frontend_type>text</frontend_type>
                        <sort_order>1</sort_order>
                        <show_in_default>1</show_in_default>
                        <show_in_website>1</show_in_website>
                        <show_in_store>1</show_in_store>
                        <comment>Username of the SMS gateway.</comment>
                    </sms_username>
                    <sms_password translate="label tooltip comment">
                        <label>Sender Email</label>
                        <frontend_type>text</frontend_type>
                        <sort_order>1</sort_order>
                        <show_in_default>1</show_in_default>
                        <show_in_website>1</show_in_website>
                        <show_in_store>1</show_in_store>
                        <comment>Password of the SMS gateway.</comment>
                    </sms_password>
                </fields>
            </sms_group>
        </groups>
    </smsconfig>
</sections>

After ben's request, we placed the adminhtml.xml file. I placed the content of the XML file.

<config>
<acl>   
    <resources>
        <admin>
            <children>
                <system>
                    <children>
                        <config>
                            <children>
                                <sms translate="title" module="sms">
                                    <title>SMS Gateway Section</title>
                                </sms>
                            </children>
                        </config>
                    </children>
                </system>
           </children>
       </admin>
   </resources>
</acl>

But till the 404 error comes...

Answer 1

A 404 error in system configuration often means that there is an issue with ACL. You are likely missing the appropriate acl node in your module's adminhtml.xml file:

<acl>
    <resources>
        <admin>
            <children>
                <system>
                    <children>
                        <config>
                            <children>
                                <smsconfig> <!-- translate="title" module="sms_config" if appropriate and depending on config -->
                                    <title>Your Section</title>
</...>

After adding the above you will need to log out and log back in for full admin role users and explicitly add this role to custom admin user roles.