[Theme Horse Support Team]

Hi info110,

That must not be an error. We have tested in our environment.

<?php
// Unhook default Thematic functions
function unhook_thematic_functions() {
    // Don't forget the position number if the original function has one

remove_action( ‘interface_404_content', ‘interface_display_404_page_content', 10 );

}
add_action('init','unhook_thematic_functions'); // removes the header content by using hook interface_header

add_action( ‘interface_404_content', ‘interface_child_display_404_page_content', 10 );
/**
 * function to show the footer info, copyright information
 */
 
 
function interface_child_display_404_page_content() {      ?>   
<div id="content">
		<header class="entry-header">
			<h1 class="entry-title"><?php _e( 'Error 404-Page NOT Found', ‘interface’ ); ?></h1>
		</header>
		<div class="entry-content clearfix" >
			<p>You page 404 is Changed. Thank you</p> 
		</div><!-- .entry-content -->
	</div><!-- #content -->
  <?php 
} ?>

The above code is just only an example to over ride page 404.php, Similarly you need to modify what you need to change. If you are unable then you need to hire a developer to fix it.

Thank you!