Generate the .htaccess file with PrestaShop’s back office, to get Friendly URL

if your website encountering some problems (white page, prestashop internal server error, some other problems) it's necessary to turn on error reporting. With this feature you will see what exactly doesnt work and
where.

so, please follow guidelines below:

prestashop max v1.5.3

open file: config/config.inc.php
find this line: @ini_set('display_errors', 'off');

change to look like this: @ini_set('display_errors', 'on');

prestashop above v1.5.3

open: config/defines.inc.php

find this line: define('_PS_MODE_DEV_', false);

change to look like this: define('_PS_MODE_DEV_', true);