n00b here. After searching the forums I have not yet come across this problem as I am experiencing it.
I have a CI site that was working correctly until about three
First Try to active error handlers for displaying of errors for addittional info to post here what error is occuring..
// change settings for error handler to show errors
// $this setup is used for checking errors for development to be shown....
ini_set('display_errors', 1);
error_reporting(E_ALL);
by the way if your using CI version 2 higher you can see it in its index.php file an configuration for displaying error also.
define('ENVIRONMENT', 'development'); //just set up environtment to development