after adding the plugin the cart page shows like this.

This is a permalink resetting problem. The plugin does not create permalink issues that I now of. But you can try this in your functions.php file:

add_action('xyz_daily_event', 'fix_perm_daily');

        function xyz_fix_perm() {
            if ( !wp_next_scheduled( 'xyz_daily_event' ) ) {
                wp_schedule_event(time(), 'daily', 'xyz_daily_event');
            }
        }

        add_action('wp', 'xyz_fix_perm');

        function fix_perm_daily() {
            global $wp_rewrite;
            $wp_rewrite->flush_rules();
        }