Checkout of all WordPress sites are down

Hello people,

Sorry, my english is not very well. I have a problem with WordPress since two weeks. All my WordPress sites suddenly has the next issues. They all worked fine and then the next pages stopped working. I think it automatically updated to 3.6 > 3.7.1 > 3.8.

All the WordPress sites are on a Virtual VPS space. 40G space and the speed is 2GHz.

WooCommerce
– checkout page is blank.
– Settings page is blank ( /wp-admin/admin.php?page=woocommerce_settings )
– Status page is blank ( /wp-admin/admin.php?page=woocommerce_status )

WordPress
– WordPress Plugin page is blank (/wp-admin/plugins.php)
– WordPress New Plugin ( /wp-admin/plugin-install.php ) works, but I can’t find any plugin. This is very strange.
– WordPress Update page is blank ( /wp-admin/update-core.php )

What I’ve did to solve this, but NOT worked.
– Hosting has increase php memory to 256MB in php.ini
– New clean WordPress installation to check if it worked with WooCommerce.
– WooCommerce support says there is something with the host provider. Even if I deactivate Woocommerce, the WP sites above are not working.

Please I hope you guys can help me solve this, as I don’t know how to fix this. Very very strange problem.

Regards,

Saci