Fixed the problem with &&rrt&& by restoring a older version of the google button file. File is google-checkout-button.php.
directory is: s2member-pro\includes\templates\buttons
this should be the code
<?php
if (realpath (__FILE__) === realpath ($_SERVER["SCRIPT_FILENAME"]))
exit ("Do not access this file directly.");
?>
<a href="%%wpurl%%/?s2member_pro_google_co=1&co[level]=%%level%%&co[ccaps]=%%ccaps%%&co[desc]=%%desc%%&co[cc]=%%cc%%&co[custom]=%%custom%%&co[ta]=%%ta%%&co[tp]=%%tp%%&co[tt]=%%tt%%&co[ra]=%%ra%%&co[rp]=%%rp%%&co[rt]=%%rt%%&co[rr]=%%rr%%&co[image]=%%image%%&co[output]=%%output%%">
<img src="https://checkout.google.com/buttons/checkout.gif?w=180&h=46&style=trans&variant=text&loc=<?php echo urlencode (_x ("en_US", "s2member-front google-button-lang-code", "s2member")); ?>" style="width:auto; height:auto; border:0;" alt="Google®" />
</a>