Page Template dropdown missing from page attribute in wordpress

Page Template dropdown missing from page attribute in wordpress:

Either you are are added any page template or format is not correct while adding page template name

It is because of space after the page template name:

wrong code :

<?php
/*
Template Name :Contact page    // No need to add space here
*/
get_header(); ?>

Proper way

<?php
/*
Template Name:Contact page
*/
get_header(); ?>