Framebuffer::Capture not capturing interface

[SpiderPig]

This code does not capture the button in the screenshot.

#include "Engine.h"

using namespace UltraEngine;

int main(int argc, const char* argv[])
{
    auto plugin = LoadPlugin("Plugins/FITextureLoader");
    //Get the displays
    auto displays = GetDisplays();

    //Create window
    auto window = CreateWindow("Ultra Engine", 0, 0, 1280, 720, displays[0]);

    //Create framebuffer
    auto framebuffer = CreateFramebuffer(window);

    //Create world
    auto world = CreateWorld();

    //Create main camera
    auto camera = CreateCamera(world);
    camera->SetPosition(0, 0, -3);

    //Create a model
    auto box = CreateBox(world);

    //Create a light
    auto light = CreateBoxLight(world);
    light->SetRange(-5, 5);
    light->SetRotation(34, 45, 0);

    //Load a font
    auto font = LoadFont("Fonts/arial.ttf");

    //Create user interface with a semi-transparent background
    auto ui = CreateInterface(world, font, framebuffer->size);
    ui->background->SetColor(0, 0, 0, 0.5);

    //Create widget
    iVec2 sz = ui->background->ClientSize();
    auto button = CreateButton("Button", sz.x / 2 - 75, sz.y / 2 - 15, 150, 30, ui->background);

    //Create camera
    auto orthocamera = CreateCamera(world, PROJECTION_ORTHOGRAPHIC);
    orthocamera->SetClearMode(CLEAR_DEPTH);
    orthocamera->SetPosition(float(framebuffer->size.x) * 0.5f, float(framebuffer->size.y) * 0.5f, 0);

    //UI will only appear in orthographic camera
    orthocamera->SetRenderLayers(2);
    ui->SetRenderLayers(2);

    while (true)
    {
        box->Turn(0, 1, 0);

        while (PeekEvent())
        {
            const Event ev = WaitEvent();
            switch (ev.id)
            {
            case EVENT_WINDOWCLOSE:
                if (ev.source == window)
                {
                    return 0;
                }
                break;
            default:
                ui->ProcessEvent(ev);
                break;
            }
        }

        if (window->KeyHit(KEY_F2)) { framebuffer->Capture(); }
        auto captures = framebuffer->GetCaptures();
        for (auto c : captures) {
            auto path = GetPath(PATH_DESKTOP) + "/screenshot.jpg";
            c->Save(path);
            RunFile(path);
        }

        world->Update();
        world->Render(framebuffer);
    }
    return 0;
}