PHP version 5.2.4 does not support CodeIgniter 4. CodeIgniter 4 has higher minimum requirements compared to CodeIgniter 3.

The reason PHP 5.2.4 is not compatible with CodeIgniter 4 is that CodeIgniter 4 has been developed using modern PHP features and functionalities that are not present in PHP versions before PHP 7.2. PHP 5.2.4 lacks the necessary language features and performance enhancements required for running CodeIgniter 4.

The minimum PHP version required to run CodeIgniter 4 is PHP 7.2 or higher. CodeIgniter 4 is compatible with PHP versions up to the latest supported PHP version at the time of its release. However, it's essential to check the official CodeIgniter documentation or release notes for the most up-to-date information regarding PHP compatibility for CodeIgniter 4, as compatibility details might change with subsequent updates or releases.