Broken on frontend

The link added is relative so it doesn’t work when the toolbar is displayed on the frontend (which is default WP behaviour these days).

For example, if you’re at http://example.com and you click the link you end up here:
http://example/options-general.php?page=wpsupercache&wp_delete_cache=1&tab=contents&_wpnonce=xxxxxxxx

To fix this, line 34 should be:

'href' => wp_nonce_url( admin_url('options-general.php?page=wpsupercache&wp_delete_cache=1&tab=contents'), 'wp-cache' )

That’ll make the link absolute.

Thanks.

https://wordpress.org/plugins/wp-super-cache-clear-cache-menu/