Fatal error: Uncaught Error: Class 'Concrete\Controller\Backend\UserInterface\File' not found in /home/optinadmin/rfl.optin.co.nz/concrete/controllers/dialog/file/thumbnails/edit.php:9 Stack trace: #0 {main} thrown in /home/optinadmin/rfl.optin.co.nz/concrete/controllers/dialog/file/thumbnails/edit.php on line 9