this is because the server has strict error reporting enabled. you should be able to talk to the host and have them set the error reporting level to not include strict errors.
or you can edit the webassist/kfm/classes/kfmSession.php file, and change line 58 - 60:
function __construct($key=''){
$this->kfmSession($key);
}
to:
if (!function_exists("__construct")) {
function __construct($key=''){
$this->kfmSession($key);
}
}