1. You login backend, then go to Advanced Parameters->Performances, set Debug mode is On, then click Save
2. Edit file config/defines.inc.php via FTP
if (!defined('_PS_MODE_DEV_')) {
define('_PS_MODE_DEV_', false);
}
Change to:
if (!defined('_PS_MODE_DEV_')) {
define('_PS_MODE_DEV_', true);
}
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