I'm following these :
*USE THE NEW ADMIN BAR: By default, BuddyPress is using the "BuddyBar". If you'd prefer to use the new admin bar, add define('BP_USE_WP_ADMIN_BAR', true); to your wp-config.php file just above where it says "That's all, stop editing! Happy blogging."
editing my wp-config.php, placing the code, saving...
but nothing changed! refreshing the page, but still nothing changed,