Call to undefined function after functions.php edit.

Hi,

So I was adding the following code to my functions.php file so that I could display a list of daily tasks in the Dashboard area, this has worked perfectly on 3 other installs and initially appeared to be working fine also.

add_shortcode('clarity','clarity_shortcode');

function my_admin_notice() {
    ?>
    <div class="updated">
        <p><?php _e( 'Daily Tasks: <strong>Item1</strong>.', 'my-text-domain' ); ?></p>
    </div>
    <?php
}
add_action( 'admin_notices', 'my_admin_notice' );

Shortly after adding the code and clicking update I went back to Appearance > Editor to make further changes to the text that was being displayed, I clicked ‘Update’ and when the site refreshed I received a ‘500 Internal Server Error’.

So naturally I went to the htaccess file to check for issues, but there are non here.

So I attempted to replace the functions.php file with a new, unedited one from the themes installation folder and now I’m recieveing this error:

“Fatal error: Call to undefined function get_template_directory() in /…/folder/members/wp-includes/functions.php on line 15”

I’ve moved:

require( ABSPATH . WPINC . ‘/plugin.php’ );

…above…

require( ABSPATH . WPINC . ‘/functions.php’ );

… in wp-settings.php but this hasn’t fixed the issue as suggested by some forum posts.

Can anyone help me fix this issue?

Thanks,

Best Regards,
AFX