What could be causing the "Maximum execution time exceeded" error in the PHP code provided?

The "Maximum execution time exceeded" error occurs when a PHP script takes longer to execute than the maximum allowed time set in the php.ini configuration file. To solve this issue, you can increase the maximum execution time limit by setting the `max_execution_time` directive to a higher value in the php.ini file or within the PHP script using the `ini_set()` function.

// Increase the maximum execution time limit to 60 seconds
ini_set('max_execution_time', 60);

// Your existing PHP code here
// ...