系统配置中出现404错误通常表示ACL存在问题.您可能在模块的adminhtml.xml文件中缺少相应的acl节点:

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>
</...>

添加上述内容后，您将需要注销并重新登录以拥有完整的管理员角色用户，并将该角色明确添加到自定义管理员用户角色中.

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.