GetQueuedCompletionStatus returns back error 327 (0x147)

I am using GetQueuedCompletionStatus like this

 BOOL ret = GetQueuedCompletionStatus(ReadPort,
                                            &NumberBytes,
                                            &Key,
                                            &CompletedOverlapped,
                                            INFINITE); 
        if (!ret)
        {
            DWORD lastError = GetLastError();
            printf("IOCP error %u\n", lastError);
            break;
        }

Every now and then I would get an error of 327 (0x147) which I am not sure why ? Any suggestions on why this might be happening ?

For reference this is 327 error description: 327 (0x147)

The command specified a data offset that does not align to the device's granularity/alignment.