Enabling debug mode in PrestaShop

  1. Open the site file config/defines.inc.php in the built-in editor filemanager or any FTPclient.
  2. Find the line with the parameter _PS_MODE_DEV_:
    define('_PS_MODE_DEV_', false);
  3. In the found line, replace false on trueso that it looks like this:
    define('_PS_MODE_DEV_', true);
  4. Save your changes.
  5. Reproduce the error on the site.

After identifying the source of errors on the site and eliminating their causes, it is recommended to disable debug mode.