What could be causing the "Allowed memory size exhausted" error in PHP when using nusoap.php?

The "Allowed memory size exhausted" error in PHP when using nusoap.php may be caused by the script using up more memory than the limit set in the php.ini configuration file. To solve this issue, you can try increasing the memory_limit value in the php.ini file or modifying the script to use less memory.

ini_set('memory_limit', '256M');