Overriding core classes

Huh... go figure. I've created MY_Controller classes on many occasions without any problem.

Line #374 from Codeigniter.php only makes the class code available, it does not instantiate it.

PHP Code:

require_once APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php'; 


The controller is instantiated on line #518

PHP Code:

$CI = new $class(); 


There's a whole bunch of error checking going on in between most of which results in a 404 if all the pieces cannot be found.

You don't mention getting any errors. Did you?