If your store or your client prestashop store have weird behaviour like product page doesnt appear (but header and index page appear) perhaps you have same problem with me. Here few step to trouble shoot it :

  1. Edit config/config.inc.php and temporarily change ‘display_errors’ from ‘off’ to ‘on’ so that you get an error message on those pages and post the errors here.
  2. My error message is Fatal error: Smarty error: [in /prestashop/themes/prestashop/./errors.tpl line 9]: [plugin] modifier ‘secureReferrer’ is not implemented (core.load_plugins.php, line 118) in /prestashop/tools/smarty/Smarty.class.php on line 1095
  3. If you have same error with me after changing the display_errors to ‘on’. Then you should check your prestashop version.
  4. My client prestashop version was 1.3.0,  if you read my previous post about prestashop important security update then you know that you must upgrade your prestashop version to the latest stable one in order to solve the problem above.