The hid_write() returns -1

[TimurAs]

Hello, could you help me please.
I've installed the hidapi into my Qt project by the instruction from here
http://www.eliasing.com/qt/hid-qt
uses the hidapi-0.7.0 version , OS Windows 10
And it compiled well, then I reading the vid and pid, but the method hid_write()
exactly gives -1. _ tried to use latest version of hidapi_ (moved the folders with my version and put instead new, then cleaned my project, rebuild, rewrite the path to file hidapi.h)
And the same history - only reading the pid and vid

`MicroCont::MicroCont(QObject *parent) : QObject(parent)
{

devs = hid_enumerate(0x0, 0x0);
cur_dev = devs;
while (cur_dev) {
    qDebug() << "vendor_id: " << cur_dev->vendor_id;
    qDebug() << "product_id: " << cur_dev->product_id;
    qDebug() << "path: " << QString(cur_dev->path);
    qDebug() << "serial_number: " << cur_dev->serial_number;
    qDebug() << "manufacturer_string: " << cur_dev->manufacturer_string;
    qDebug() << "product_string: " << cur_dev->product_string << "\n";

    cur_dev = cur_dev->next;
}
hid_free_enumeration(devs);

//---------------------------------------------------------------------------------

res = hid_init();
qDebug() << res << 1;

handle = hid_open(0x046d, 0xc31c, NULL); 

if (handle == NULL) qDebug() <<"Handle is Null";
else
    qDebug() << "Hid opened: "<< handle;

}

MicroCont::~MicroCont()
{
res = hid_exit();
qDebug () << "hid exit: " << res << 3;
}

void MicroCont::writeHID() //THIS IS SLOT function, SO I USE IT BY THE BOTTON PUSH
{
// Read the Manufacturer String
res = hid_get_manufacturer_string(handle, wstr, MAX_STR); //THIS IS WORK
qDebug("\nManufacturer String: %ls", wstr);

    // Toggle LED (cmd 0x80). The first byte is the report number (0x0).
    buf[0] = 0x0;
    buf[1] = 0x80;

    res = hid_write(handle, buf, 65); //but this is NOT work
    qDebug () << res << 2;

}
`
I tried to write some command to my device, but it's owful. Please help, my brain is going to booom...

[ikillmeba]

guys, should notice the report id(maybe 0) and length(may be 65) of written on windows