Call to undefined function wp() in wp-blog-header.php

I am getting this error:

Fatal error: Uncaught Error: Call to undefined function wp() in /home/pgcimykfka2h/public_html/apni-rasoi.com/wp-blog-header.php:16 Stack trace: #0 /home/pgcimykfka2h/public_html/apni-rasoi.com/index.php(24): require() #1 {main} thrown in /home/pgcimykfka2h/public_html/apni-rasoi.com/wp-blog-header.php on line 16