bug crash help programmer?

[Sigoles]

Today I got one bug/crash with this function on c++

void ProtocolGame::updateCoinBalance()
{
    NetworkMessage msg;
    msg.addByte(0xF2);
    msg.addByte(0x00);
 
    writeToOutputBuffer(msg);
 
    g_dispatcher.addTask(
        createTask(std::bind([](ProtocolGame_ptr client) {
            auto coinBalance = IOAccount::getCoinBalance(client->player->getAccount());
            client->player->coinBalance = coinBalance;
 
            client->sendCoinBalance();
        }, getThis()))
    );
}

See any error programmers? Thanks for who will help