Google Plus One script has quit working, now returns red flag

Google +1 is very easy to add to your site, you only need 2 things for a basic button.

1. Google’s JavaScript, make sure its is https not http!

`<script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script>`

To add this to your site in your functions.php you can write,

function google_plus_gp() {
        wp_register_script( 'google-plus', 'https://apis.google.com/js/plusone.js');
    wp_enqueue_script('google-plus')
}
add_action ('wp_enqueue_scripts','google_plus_gp');

2. The markdown where you want the button.

<g:plusone></g:plusone>

You can add something like a content filter for after your posts.

add_filter('the_content', 'google_plus_plus');
function google_plus_plus($content) {
    $content = $content.'<div class="plusone"><g:plusone href="'.get_permalink().'"></g:plusone></div>';
    return $content;
}