Your new environment may have E_STRICT warnings enabled in error_reporting if it is php <= 5.3, or if simply have error_reporting set to at least E_WARNING with PHP 5.4+. . That error is triggered when $res is NULL or not yet initialized:
$res = NULL;
$res->success = false; // Warning: Creating default object from empty valuePHP will report a different error message if $res is already initialized to some value but is not an object:
$res = 33;
$res->success = false; // Warning: Attempt to assign property of non-objectIn order to comply with E_STRICT standards prior to PHP 5.4, or the normal E_WARNING error level in PHP >= 5.4, assuming you are trying to create a generic object and assign the property success, you need to declare $res as an object of stdClass:
$res = new stdClass();
$res->success = false;