Fix bugs: White page, Blank Page in magento

In file index.php. You recomment // ini_set('display_errors', 1);
Result: ini_set('display_errors', 1);

Check erros code of white page. Make sure codes of Core Magento, Modules, ... are true.

Clear cache, Reindex in Admin magento. Remove caches in magento/var/cache/*

FINAL: Permision files of magento. Link
https://letunhatkong.blogspot.com/2015/07/permission-file-and-folder-in-magento.html