What theme are you using?

Go to your Appearance settings then to Editor and then search for the single.php on the right side and click on this file and then search for “<? }” and change it to to “<?php }”.

and in dashbord all time i have this error

Notice: Undefined index: page in /var/www/html/wp-content/themes/zingtube/functions.php on line 185

block 185-192 functions.php

if( $_GET[‘page’] == ‘theme-options’ && isset($_POST[‘submit’]) ) {
update_option( ‘bg_color’, $_POST[‘bg_color’] );
update_option( ‘body_color’, $_POST[‘body_color’] );
update_option( ‘main_color’, $_POST[‘main_color’] );
update_option( ‘hf_bg’, $_POST[‘hf_bg’] );
update_option( ‘second_color’, $_POST[‘second_color’] );
wp_redirect( ‘admin.php?page=theme-options&saved=true’ );
}