WSARecv() failed with error 10038

clients[target].Socket = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, NULL, WSA_FLAG_OVERLAPPED);
 
 
    sockaddr_in m_saddr;
    ZeroMemory(&m_saddr, sizeof(m_saddr));
 
    m_saddr.sin_family = AF_INET;
    m_saddr.sin_addr.s_addr = ipv4_addr;
    m_saddr.sin_port = port;
 
    if (connect(clients[target].Socket, (sockaddr*)&m_saddr, sizeof(m_saddr)) != SOCKET_ERROR)
    {
        clients[target].auth = true;
        clients[target].ID = *(unsigned int*)src;
        //loc_sock[target].delay = time(0);
 
        if (core <= 2)
            CreateIoCompletionPort((HANDLE)clients[target].Socket, iocp[0], 0, 0);
        else
            CreateIoCompletionPort((HANDLE)clients[target].Socket, iocp[target % (core-2)], 0, 0);
 
        return target;
    }
return -1;

LPPER_IO_OPERATION_DATA op = (LPPER_IO_OPERATION_DATA)GlobalAlloc(GPTR, sizeof(PER_IO_OPERATION_DATA));
    
    DWORD flags;
    unsigned long b;
    ZeroMemory(op, sizeof(PER_IO_OPERATION_DATA));
    op->op_type = PER_IO_OPERATION_DATA::op_type_recv;
    op->wsabuf.buf = op->buff;
    op->wsabuf.len = BUFF_SIZE - 6;
    flags = 0;
    if (WSARecv(clients[target].Socket, &(op->wsabuf), 1, &b, &flags, (OVERLAPPED*)op, NULL) == SOCKET_ERROR)
    {
        if (WSAGetLastError() != ERROR_IO_PENDING)
        {
            printf("WSARecv() failed with error %d\n", WSAGetLastError());
        }
        else
            printf("WSARecv() failed with error %d\n", WSAGetLastError());
    }
    else
        printf("WSARecv() is OK!\n");