Fatal error: Call to undefined function get_current_screen() in admin-bar.php on

How are you?
“Fatal error: Call to undefined function get_current_screen () in admin-bar.php on line 426”
Manager page, correct the error and the site does not open, I ask
Site Address http://eu4989.cafe24.com/wp/
Raja tube site address http://eu4989.cafe24.com/wp/wp-admin/
Error and / home/hosting_users/eu4989/www/wp/wp-includes/admin-bar.php on line 426
The admin-bar.php lines 422-434 to the current contents
function wp_admin_bar_edit_menu( $wp_admin_bar ) {
global $tag, $wp_the_query;

if ( is_admin() ) {
$current_screen = get_current_screen();
$post = get_post();

if ( ‘post’ == $current_screen->base
&& ‘add’ != $current_screen->action
&& ( $post_type_object = get_post_type_object( $post->post_type ) )
&& current_user_can( $post_type_object->cap->read_post, $post->ID )
&& ( $post_type_object->public )
&& ( $post_type_object->show_in_admin_bar ) )
http://blog.naver.com/bigsam7/110172224978 is attached to the admin-bar.php
Have been working on this error: wp touch or wp mobile edition plugin settings after entering the mobile sub domain is not connected, leave the back blank save and an error has occurred
Please help just can not be resolved would be appreciated
Thanks in advance Greetings