Network request in threads is crashing my application

Currently I have a code that is crashing (SEGFAULT) on me.

I am trying to compare a big amount of images that are in my drive to their counter parts in a server.

To speed up the process I get the image from the server and compare the images on a different thread.

From what I already tried and debugged, the issue is in getting the image from the server (that is why the other calls are commented out).

Also if I run without the QtConcurrent::run it does not crash, but if I put semaphore concurrentComparisons with only one resorce, it will crash.

Finally I also get the following errors

QObject::connect: Cannot connect (null)::configurationAdded(QNetworkConfiguration) to QNetworkConfigurationManager::configurationAdded(QNetworkConfiguration)
QObject::connect: Cannot connect (null)::configurationRemoved(QNetworkConfiguration) to QNetworkConfigurationManager::configurationRemoved(QNetworkConfiguration)
QObject::connect: Cannot connect (null)::configurationChanged(QNetworkConfiguration) to QNetworkConfigurationManager::configurationChanged(QNetworkConfiguration)
QObject::connect: Cannot connect (null)::onlineStateChanged(bool) to QNetworkConfigurationManager::onlineStateChanged(bool)
QObject::connect: Cannot connect (null)::configurationUpdateComplete() to QNetworkConfigurationManager::updateCompleted()

Any help would be very appreciated.....

Relevant code:

QSemaphore FileComparisonInfo::concurrentComparisons(1);

---

QtConcurrent::run( [this, localPath, imageURL]()
{
  ImageComparer cmp;

  FileComparisonInfo::concurrentComparisons.acquire();

  //cmp.setImageLeftPath(localPath);
  cmp.setImageRightPath(imageURL);
  //cmp.createDifferenceImage();

  FileComparisonInfo::concurrentComparisons.release();
});

---

void ImageComparer::setImageRightPath(QString path)
{
    this->rightImagePath = path;
    this->imageRight = getImage(path);
}

---

QImage* ImageComparer::getImage(QString path)
{
    QUrl url(path);
    QFile file(path);

    if(file.exists())
    {
        return new QImage(path);
    }
    else if(url.isValid())
    {
        return getImageFromURL(path);
    }
}

---

QImage* ImageComparer::getImageFromURL(QString url)
{

    QNetworkAccessManager * tempNAM = new QNetworkAccessManager();
    QNetworkReply *imageConnection = tempNAM->get( QNetworkRequest( QUrl( url ) ));

    QEventLoop loop;
    connect(imageConnection, SIGNAL(finished()), &loop, SLOT(quit()));
    loop.exec();

    QImage * downloadedImage;
    if(imageConnection->error() != QNetworkReply::NoError)
    {
        qDebug() << imageConnection->errorString();
        downloadedImage = new QImage();
    }
    else
    {
        QByteArray data = imageConnection->readAll();
        downloadedImage = new QImage(QImage::fromData(data));
    }

    tempNAM->deleteLater();
    imageConnection->deleteLater();

    return downloadedImage;
}