WordPress memory exhausted error by increasing PHP memory limit

Indications of this error could be a white screen of death, or an error message like this one: Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2348617 bytes) in /home/username/public_html/site_folder/wp-includes/plugin.php on line xxx

Increase PHP Memory Limit in WordPress

define( 'WP_MEMORY_LIMIT', '256M' );

This code tells WordPress to increase the PHP memory limit to 256MB.