title: Codeigniter: fatal error call to undefined function mysqli_init()
body: <p>I just changed my server and experience these errors below:</p>
  
  <pre><code>Fatal error: Call to undefined function mysqli_init() in /home/blacktwitter/public_html/system/database/drivers/mysqli/mysqli_driver.php on line 126
  A PHP Error was encountered
  
  Severity: Warning
  
  Message: Cannot modify header information - headers already sent by (output started at /home/blacktwitter/public_html/system/database/drivers/mysqli/mysqli_driver.php:126)
  
  Filename: core/Common.php
  
  Line Number: 564
  
  Backtrace:
  
  A PHP Error was encountered
  
  Severity: Error
  
  Message: Call to undefined function mysqli_init()
  
  Filename: mysqli/mysqli_driver.php
  
  Line Number: 126
  
  Backtrace:
  </code></pre>
  
  <p>Website is in Codeigniter. It works on one server very well and on the local machine too. But when I upload that website at the new server I have that errors. Of course I changed important parameters like database connection, base_url() etc.</p>
  
  <p>I was suspicious about database, but I have created a new database and user etc. and changed connection info. </p>
  
  <p>Why does this happen? It will be helpful to know if it is a bug at the server or at the website. Also when I create some index.html with some test code everything is fine. </p>