[14:12:47] [Server thread/CRITICAL]: ErrorException: "Creating default object from empty value" (EXC

PHP:

public function createChest(Player $player, array $items, int $id)
    {
        $this->clearData($player);
        $this->inv[$player->getName()] = $player->getInventory()->getContents();
        $v3 = $this->getVector($player);
        $this->chest[$player->getName()] = [$id, $v3];
        $this->updateBlock($player, 54, $v3);
        $pk = new ContainerOpenPacket;
        $pk->windowid = 10;
        $pk->type = 0;
        $block->x = ( int ) $v3->x;
        $block->y = ( int ) $v3->y;
        $block->z = ( int ) $v3->z;
        $player->dataPacket($pk);
        $pk1 = new ContainerSetContentPacket;
        $pk1->windowid = 10;
        $pk1->slots = $items;
        $pk1->targetEid = $id;
        $player->dataPacket($pk1);
    }
    public function updateBlock(Player $player, int $id, Vector3 $v3){
        $block->x = ( int ) $v3->x;
        $block->y = ( int ) $v3->y;
        $block->z = ( int ) $v3->z;
        $pk = new UpdateBlockPacket();
        $pk->blockId = $id;
        $pk->blockData = (int) 0xb << 4 | (0 & 0xf);
        $player->dataPacket($pk);
    }
    public function getVector(Player $player): Vector3
    {
        return new Vector3($player->x, $player->y - 3, $player->z);
    }
    public function clearData(Player $player)
    {
        if (isset($this->chest[$player->getName()]))
            unset($this->chest[$player->getName()]);
        if (isset($this->inv[$player->getName()]))
            unset($this->inv[$player->getName()]);
    }

 

$block is not defined, it is not used either, why is it there?
To easily create inventory menus i suggest using https://github.com/Muqsit/InvMenu

 

But i don't understand to create gui in invmenu muqsit