header bu şekilde oldu:

/**
* Theme Header Section for our theme.
*
* Displays all of the section and everything up till

*
* @package ThemeGrill
* @subpackage ColorMag
* @since ColorMag 1.0
*/
?>
>


<script></script>



/**
* This hook is important for wordpress plugins and other many things
*/
wp_head();
?>
<script></script>
<script></script>

<script>
$(document).ready(function() {
$('ul#controls a').fontSizer();
});
</script>



>

/**
* WordPress function to load custom scripts after body.
*
* Introduced in WordPress 5.2.0
*
* @since ColorMag 1.4.0
*/
if ( function_exists( 'wp_body_open' ) ) {
wp_body_open();
}
?>








// Add the main total header area display type dynamic class.
$main_total_header_option_layout_class = get_theme_mod( 'colormag_main_total_header_area_display_type', 'type_one' );

$class_name = '';
if ( $main_total_header_option_layout_class == 'type_two' ) {
$class_name = 'colormag-header-clean';
} else if ( $main_total_header_option_layout_class == 'type_three' ) {
$class_name = 'colormag-header-classic';
}
?>










content-single.php ise dediğiniz gibi aynen yaptım.
hata yok oldu şimdi. ancak + - gelmedi :(