Warning: include_once(Mage/Core/functions.php): failed to open stream: No such file or directory in /home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/Mage.php on line 50

Warning: include_once(): Failed opening 'Mage/Core/functions.php' for inclusion (include_path='/home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/code/local:/home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/code/community:/home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/code/core:/home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/lib:.:/opt/alt/php73/usr/share/pear') in /home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/Mage.php on line 50

Fatal error: Uncaught Error: Class 'Mage_Core_Model_App' not found in /home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/Mage.php:418 Stack trace: #0 /home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/Mage.php(443): Mage::app('', 'store', Array) #1 /home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/index.php(52): Mage::run() #2 {main} thrown in /home/db0xxnyat2cx/domains/magento.retailbagspecialist.net/html/app/Mage.php on line 418