CodeIgniter3 HMVC模式下404错误问题求助

Let’s break down the most common fixes for the 404 error you’re facing in your CodeIgniter 3 HMVC project running on PHP7. I’ve worked through similar issues before, so here’s a step-by-step checklist to get things working:

1. Fix the base_url Configuration #

Your current config.php has an empty base_url, which is a frequent culprit for routing issues in CI3—especially with HMVC. CodeIgniter relies on this value to properly resolve URIs and load HMVC modules correctly.

Update it to your actual project URL:

$config['base_url'] = 'http://localhost/your-project-name/'; // For local development
// OR
$config['base_url'] = 'https://your-production-domain.com/'; // For live site

2. Adjust the uri_protocol Setting #

The AUTO setting for uri_protocol can be inconsistent across different server environments (Apache, Nginx, etc.). It might fail to detect the correct URI format, leading to unrecognized routes.

Try switching to REQUEST_URI first:

$config['uri_protocol'] = 'REQUEST_URI';

If that doesn’t work, test PATH_INFO instead—this is often more reliable for HMVC setups.

3. Verify HMVC Controller Structure #

Since you’re using HMVC, make sure your service controller follows the correct directory and naming conventions:

• The controller file must be at application/modules/service/controllers/Service.php
• The class name must be Service (首字母大写, matching the filename)
• The default method should be index() (this runs when you hit the base URL)

Example of a valid Service.php controller:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Service extends MX_Controller {
    public function index() {
        echo "Hello from Service Controller!";
    }
}

If the filename or class name is lowercase (e.g., service.php or class service), CI3 won’t recognize it, triggering a 404.

4. Tweak the .htaccess Rewrite Rule #

Your current .htaccess rule uses a slash after index.php, which might not work on all Apache configurations (especially newer versions). Try replacing the rewrite rule with this version (using a ? instead of /):

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond $1 !^(index\.php|resources|robots\.txt)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?$1 [L,QSA]
</IfModule>

Also, confirm that the mod_rewrite module is enabled on your server. You can check this via phpinfo() or by asking your hosting provider.

5. Enable Debug Logs to Diagnose Hidden Issues #

If the above steps don’t resolve the 404, turn on CodeIgniter’s logging to catch any underlying errors that might be causing the issue:

$config['log_threshold'] = 2; // Logs errors and debug messages

Check the application/logs directory for recent log files—they might reveal problems like missing modules, syntax errors in your controller, or permission issues.

6. Test with 404 Override (Temporary) #

As a quick test, set the 404_override route to your service controller to see if CI can locate it:

$route['404_override'] = 'service';

If your service controller loads now, it means the original routing logic is failing—double-check your default_controller setting and ensure the HMVC module is properly registered.

内容的提问来源于stack exchange，提问作者Sanhita Sinha