Views are not Loading

[eluser]Greendots[/eluser]
My website has unexpectedly stopped loading my view files.

Code:

echo "1," ;
  $this->load->view("__header.php")  ;
  echo "2," ;
  $this->load->view("subfolder/my_view") ;
  echo "3," ;
  $this->load->view("__footer.php") ;
  echo "4" ;

will output:

Code:

1,2,3,4

The view files worked previously and generate valid xhtml. My admin pages work fine, but not any of the others. No changes have been made to the code.

Any idea how to troubleshoot this? My knowledge of CI is all over the place. I have invested a lot of time developing this website and learning CI as I went along, so I'm more than happy to get down and dirty with it.

-Thanks