BinaryStream.php on line 367 error

Code:

[Server thread/CRITICAL]: Could not pass event 'pocketmine\event\player\PlayerJoinEvent' src/pocketmine/utils/BinaryStream.php on line 367

[07:45:55] [Server thread/CRITICAL]: TypeError: "Argument 1 passed to pocketmine\utils\Binary::writeVarLong() must be of the type integer, null given, called in src/pocketmine/utils/BinaryStream.php on line 367" (EXCEPTION) in "/src/pocketmine/utils/Binary" at line 546

PHP:

$ev->getPlayer()->setGamemode("1");
$pk = new ContainerSetContentPacket();
$pk->windowid = ContainerSetContentPacket::SPECIAL_CREATIVE;
$ev->getPlayer()->dataPacket($pk);

 

why it is not working?
this code worked before the 1.1 update

 

never mind fixed

 

$pk->targetEid = $ev->getPlayer()->getId();