About phpBB error redirecting to potential insecure url ...

[axew3]

There is possibility that you get error tried to redirect to potentially insecure URL on phpBB redirect, when login is done via WP_w3all login widget.
There is nothing of potentially insecure redirecting to your own domain or subdomain url. But by default phpBB do not let redirect out of his install folder. As the comment explain about this function, at line 2283 of file phpBB includes/functions.php:

* This function is intended for urls within the board. It's not meant to redirect to cross-domains.

If you find out a different way, secure as the one i suggest on wp_w3all procedure, and better than this to redirect external phpBB, just suggest it please. In the while the procedure to follow is here:
phpbb login-redirect
There are tons of posts about this argument www. I have resolve in this way at moment.

[axew3]

The hint solution has been updated.