Wordpress: "Fatal error: Allowed memory size..." anytime I try to register and enqueue script in functions.php file

Every time I try to register and enqueue script in my function.php file I get the error

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 261904 bytes) in C:\Program Files (x86)\Apache Software Foundation\Apache2.2\htdocs\namewebsite\wp-includes\class.wp-dependencies.php on line 178

here is the code used in my functions.php file

function load_external_js() { // load external file  
    wp_enqueue_script('jquery');
    wp_register_script('hash-change', get_template_directory_uri() . '/js/jquery.hashchange.event.plugin.js', array('hash-change'), '', true );
    wp_enqueue_script('hash-change');
    wp_register_script('ajax-theme', get_template_directory_uri() . '/js/ajax-implementation.js', array('ajax-theme'), '', true );
    wp_enqueue_script('ajax-theme');
}  
add_action('wp_enqueue_scripts', 'load_external_js');

How can I fix this?