The latest version of Prestashop 1.5.0.9 is currently in beta, and may therefore have some problems during installation. During our testing, we ran into one of those bugs, An error occurred during installation. This article has more information about the error we faced and how we resolved it.

Problem:

The installation stops during installation at 50% with the following error:
"An Error occurred during installation..."   - further detail on the issue shows this:  "1. SQL errror on query  Table "xxx_xxxxx" already exists"

Solution:

The solution to this problem involves editing /install/models/install.php

Open that file for edit, and at line 400, you'll see the following:

$localization_file_content = @Tools::file_get_contents('http://api.prestashop.com/download/localization/'.$version.'/'.$data['shop_country'].'.xml');