Fixing the blank white screen BUG on PrestaShop

 Prestashop is a very useful e commerce software. One of the common errors while fresh installation or upgrade  is a white screen. This is very disturbing to as there is  no error message telling you what is wrong.
 Mostly it is due to program running out of allowed memory as Prestashop 1.6 is a  bit more memory intensive than previous versions. This article will show you how to update your server for memory_limit to fix the most common cause of the white screen error.

Check PHP memory_limit

To know the value of PHP memory_limit, you can check the configuration in PHP.ini. However, sometimes you might not know where php.ini is located. So, the simplest way is to use execute PHP function phpinfo(), which will display all the php related server configuration.

<?php phpinfo(); ?>

How much memory do I need?

 It depends on many factors 

1. CPU process times of your server host.

2. Your theme (some themes are well coded, some of them not. In addition, some themes use own customized modules, sometimes they affecting performance)

Increase PHP memory_limit

 Modify php.ini

Step 1. Firstly you need find your php.ini . In the report generated by phpinfo() (you can use PHP script created in above), there is a parameter called “Loaded Configuration File”, that’s where your PHP.ini file is located. If you use Linux, you can simple run the command “php -i | grep Loaded Configuration File” to find it.For windows user, you can find it in your php install directory.

Step 2 :Edit php.ini 

Search “memory_limit” in your php.ini, and change the value of it. If no “memory_limit” found, add the following line at the end of php.ini  

memory_limit = 128M ; /* Change the 128M to your needs */

Save file.

Step 3:  Restart Apache. Use follow command to restart apache：

httpd restart