Mithrandir wrote:
First job for the beta testing team, until we get the infrastructure finalised:

Could you try replacing

if (!strpos(XOOPS_URL, "http")) {
        //Relative URL used, calculate absolute URL
        $protocol = strtolower(substr($_SERVER['SERVER_PROTOCOL'], 0, strpos($_SERVER['SERVER_PROTOCOL'], "/", 0)));
        define("XOOPS_ABS_URL", $protocol."://".$_SERVER['HTTP_HOST'].XOOPS_URL);
    }
    else {
        define("XOOPS_ABS_URL", XOOPS_URL);
    }

with

if (strpos(XOOPS_URL, "http") === 0) {
        define("XOOPS_ABS_URL", XOOPS_URL);
    }
    else {
        //Relative URL used, calculate absolute URL
        $protocol = strtolower(substr($_SERVER['SERVER_PROTOCOL'], 0, strpos($_SERVER['SERVER_PROTOCOL'], "/", 0)));
        define("XOOPS_ABS_URL", $protocol."://".$_SERVER['HTTP_HOST'].XOOPS_URL);
    }

in include/common.php (around lines 119-126)

Then see if it fixes the activation link as well as other links in emails.

Thanks