I had to delete the app.php file and then restore it.
now I have a fully functioning back end but the front end shows the below code.
Warning: include(Mage/Core/Model/App.php): failed to open stream: No such file or directory in /home2/sportpat/public_html/clubdoncastershop/lib/Varien/Autoload.php on line 94
Warning: include(): Failed opening 'Mage/Core/Model/App.php' for inclusion (include_path='/home2/sportpat/public_html/clubdoncastershop/app/code/local:/home2/sportpat/public_html/clubdoncastershop/app/code/community:/home2/sportpat/public_html/clubdoncastershop/app/code/core:/home2/sportpat/public_html/clubdoncastershop/lib:.:/usr/php/54/usr/lib64:/usr/php/54/usr/share/pear') in /home2/sportpat/public_html/clubdoncastershop/lib/Varien/Autoload.php on line 94
Fatal error: Class 'Mage_Core_Model_App' not found in /home2/sportpat/public_html/clubdoncastershop/app/Mage.php on line 670
does anyone have an idea why its happened and how to fix it?
much appreciated in advance!!! THANKS EVERYONE