Enable Debugging for PrestaShop

Here we will cover how to identify potential causes of a blank or white page or an error 500 on a PrestaShop website by enabling debugging mode to view the error reporting in PrestaShop versions 1.5.3. to 1.7.

This issue can be caused by a number of reasons ranging from issues with PHP, .htaccess, themes, missing PHP modules, file/folder permissions, and even corrupted files.

To determine the exact reason, it is best to obtain a specific error message. Enabling error reporting in PrestaShop as outlined below can provide this.

Related Articles

PrestaShop Reset Admin Password
Reset PrestaShop Admin Email Address
Force HTTPS on a PrestaShop Site

Enabling Debugging in Versions 1.7.x

1. Log into the PrestaShop Admin dashboard
   NOTE: If you cannot access the PrestaShop Admin dashboard, try using the alternate debugging method below for versions 1.5.3 to 1.6.
2. Locate the CONFIGURE menu on the left-hand side
3. Expand the Advanced Parameters option
4. Select Performance
   
   
5. Open the Debug Mode section
6. Toggle the Debug mode option to Yes
   
   
7. Click Save
   IMPORTANT: When finished debugging, set the Debug mode option back to No and Save the changes!

Enabling Debugging in Versions 1.5.3 to 1.6

1. Access the site's files using FTP or through File Manager
   
2. Find the defines.inc.php file in the Prestashop site's config directory
   EXAMPLE: public_html/config/defines.inc.php
3. Right-click and Edit the file
   
4. Change define(‘_PS_MODE_DEV_’, false); to define(‘_PS_MODE_DEV_’, true);
   TIP: This is usually around line 29 in the file.

   
   

5. Save the changes to the file
   
6. After saving, reload the website
   1. The page/site should now display errors instead of a blank/white screen to review and troubleshoot accordingly
      CAUTION:  When finished debugging, change define(‘_PS_MODE_DEV_’, true); back to define(‘_PS_MODE_DEV_’, false); and Save the changes

Enabling Debugging in Version 1.5.3

1. Access the site using FTP or through File Manager
2. Find the defines.inc.php file in the Prestashop site's config directory
3. Right-click and Edit the file
   
4. Change @ini_set('display_errors', 'off'); to @ini_set('display_errors', 'on');
5. Save the changes to the file
   
6. After saving, reload the website
   1. The page/site should now display errors instead of a blank/white screen to review and troubleshoot accordingly
      CAUTION: When finished debugging, change @ini_set('display_errors', 'on'); back to @ini_set('display_errors', 'off'); and Save the changes.

This article covers PrestaShop versions 1.5.3 - 1.7.x.
If an updated version is available and not documented here, drop us a comment so we can work to get it updated for you as soon as possible!