Symptoms

When you are trying to start Apache, the following error appears in the apache error log:

PHP Fatal error: [ionCube Loader] The Loader must appear as the first entry in the php.ini file in Unknown on line 0

Cause

This error occurs because your php extensions are loading in the wrong order in your PHP configuration.

Resolution

Zend extensions can be loaded directly from /etc/php.ini file, or included from /etc/php.d/ directory.

In this example this 'ioncube' line must appear before any Zend configuration sections, which usually begin with [Zend] so they should be easy to see:

zend_extension=/usr/lib/ioncube/php_ioncube_loader_lin_X.X.so

If extensions are loaded from /etc/php.d, they are loaded in alphabetical order.  Usually the 'ioncube' file is named /etc/php.d/ioncube.ini and zend is /etc/php.d/zend.ini. In this scenario it should not present a problem.

Finally, make sure that 'ioncube' is loaded only once.  The following command should only return one result:

grep 'zend_extension.*ioncube' /etc/php.ini /etc/php.d/* 

If you make any configuration changes always be sure to restart Apache:

 /etc/init.d/httpd restart