nvxio::createImageRender error codes & description

Hello folks,
I’m trying to use nvxio to output image to jpeg file.
The problem is that nvxio::createImageRender returns null and I can’t get an info why.
My code is:

int main()
{
    auto context = make_guard(vxCreateContext(), vxReleaseContext);
    std::cout << "context = " << (void*)(vx_context)context << std::endl;
    vxRegisterLogCallback(context, &nvxio::stdoutLogCallback, vx_false_e);
    std::string name = "test.jpg";
    auto render = nvxio::createImageRender(context, name, 1024, 768, VX_DF_IMAGE_RGBX);
    std::cout << "render = " << render.get() << std::endl;
}

The output is:

context = 0x24b95d0
VisionWorks library info:
         VisionWorks version : 1.5.3
         OpenVX Standard version : 1.1.0

render = 0

This is strange that the null pointer is returned rather than exception thrown.
Am I supposed to check some global status? Is it thread-bound?