I replaced
//make the new column sortable
function user_sortable_columns( $columns ) {
$columns['login_level'] = 'login_level';
return $columns;
}
add_filter( 'manage_users_sortable_columns', 'user_sortable_columns' );
//set instructions on how to sort the new column
function my_user_query($userquery){
if('login_level' == $userquery->query_vars['orderby']) {
global $wpdb;
$userquery->query_from .= " LEFT OUTER JOIN $wpdb->usermeta AS alias ON
($wpdb->users.ID = alias.user_id) ";//note use of alias
$userquery->query_where .= " AND alias.meta_key = 'login_level' ";//which meta are we sorting with?
$userquery->query_orderby = " ORDER BY alias.meta_value ".($userquery->query_vars["title"] == "ASC" ? "asc " : "desc ");//set sort order
}
}
with
//make the new column sortable
function prefix_sortable_columns( $columns ) {
$columns['login_level'] = 'login_level';
return $columns;
}
add_filter( 'manage_users_sortable_columns', 'prefix_sortable_columns' );
function prefix_sort_by_level( $query ) {
if ( 'login_level' == $query->get( 'orderby' ) ) {
$query->set( 'orderby', 'meta_value' );
$query->set( 'meta_key', 'level' );
}
}
add_action( 'pre_get_users', 'prefix_sort_by_level' );
And it’s done.