Trying to increase WP Memory Limit

Try adding to wp-includes/default-constants.php
You’ll probably see the default values of 40M starting around line #20, change these values. My setup is as follows:

// set memory limits
    if ( !defined('WP_MEMORY_LIMIT') ) {
        if ( is_multisite() ) {
            define('WP_MEMORY_LIMIT', '256M');
        } else {
            define('WP_MEMORY_LIMIT', '256M');
        }
    }