Yesterday I changed my index.php file to make it available to the specific IP addresses written in the Developer options of the Admin Panel.

I changed

if (file_exists($maintenanceFile)) {

to

if (file_exists($maintenanceFile) && !(Mage::helper('core')->isDevAllowed())) {

and moved

require MAGENTO_ROOT . '/app/bootstrap.php';

require_once $mageFilename;

at the top of the changed condition.

My website did what I wanted it to do for the following hours, but when I woke up this morning nothing worked. The error message is

Fatal error: Class 'Mage_Eav_Model_Entity_Setup' not found in /includes/src/Mage_Core_Model_Resource_Setup.php

I set the index.php file like it was before the changes but the problem remains the same.

Is there any way I can fix that?

Thanks.

Cg