How to Diagnose a Blank Page

Introduction

In this article, we will look at how to diagnose a blank page in your CMS.

We will explain how to activate debug mode in 3 of the most popular CMS: WordPress, Joomla! and PrestaShop. In all three cases, you will need to access your hosting’s FTP via FileZilla (or another FTP client) or the file manager.

WordPress

1. Right-click on the wp-config.php file in the location where your site is installed.
2. Modify the following line:

define( 'WP_DEBUG', false );

  For :

define( 'WP_DEBUG', true );

4. Save.
5. Do not forget to set the parameter to false after debugging.

Joomla!

1. Edit the configuration.php file.
2. Modify the variable :

public $debug = '0';

For :

public $debug = '1';

4. Save.
5. Do not forget to set the parameter to 0 after debugging.

If you have access to the Joomla! Administration menu, go to Menu -> General configuration, System tab, Debugging parameters block, and activate System debugging.

Prestashop

1. In your PrestaShop installation folder, navigate to the config folder and edit the defines.inc.php file.
2. Modify the following line :

define('_PS_MODE_DEV_', false);

For

define('_PS_MODE_DEV_', true);

4. Save.
5. Do not forget to set the parameter to false after debugging.

You can also refer to the official Prestashop Troubleshooting guide. Additional information is also available on their blog for this type of situation: La page blanche et les erreurs qu’elle cache pour protéger votre boutique en ligne.