title: Fatal error: Call to undefined function wp_initial_constants() in /home/site/public_html/wp-settings.php on line 26
body: <p>While updating WordPress 3.6.1 on my site I am getting the following error and the site crashes. Why is this happening to my site, and how can I overcome this problem?</p>
  
  <p>Following error arises:</p>
  
  <blockquote>
    <p>Fatal error: Call to undefined function wp_initial_constants() in /home/adventec/public_html/wp-settings.php on line 26</p>
  </blockquote>