title: Fatal error: Call to undefined function mb_strtolower()
body: <p>i have a vps server i installed nginx + php-fpm now i have a problem with mb_strtolower() function  this is my php info pleas goto this adress to see my php info </p>
  
  <pre><code>http://207.182.153.237/test.php
  </code></pre>
  
  <p>how to fix this error?</p>