Loading QQmlExtensionPlugin via QPluginLoader triggers exception

Question

Context: I am currently working on a qmlextensionplugin with a c++ backend. The plugin manages a QList and instantiates for each entry a qml visualisation. I was already able to make the list fully functional in qml.

Problem: The last thing I am missing is to update the list via c++. For that I came across this thread, so I tried to follow this example. Unfortunately I can´t even start the application due to the following exceptions.I marked the occurence location in the source code.

Why am I getting those exceptions and how can I fix them?

Snippet of the source code:

Here my implementation to load the plugin in main.cpp:

#include "NameListInterface.h"
#include <QGuiApplication>
#include <QPluginLoader>
#include <QQmlApplicationEngine>
#include <QLibraryInfo>
#include <QDebug>

void LoadPlugin(){
    NameListInterface* pluginVersion = nullptr;
#ifdef Q_OS_MACOS
    const QString fileSuffix = ".dylib";
#else
    const QString fileSuffix = ".dll";
#endif
    QPluginLoader qmlPlugin(path + "NameList/NameListPlugin.dll");
    qmlPlugin.load();
    if (qmlPlugin.isLoaded()) {
        pluginVersion = qobject_cast<NameListInterface*>(qmlPlugin.instance());//**EXCEPTION OCCURS HERE**
    } else {
        qmlPlugin.setFileName(QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath) + "/fx/my/libmyplugin" + fileSuffix);
        qmlPlugin.unload();
        qmlPlugin.load();
        if (qmlPlugin.isLoaded()) {
            pluginVersion = qobject_cast<NameListInterface*>(qmlPlugin.instance());
        } else {
            qDebug() << "ERROR while opening plugin: " << qmlPlugin.errorString();
        }
    }
    if (pluginVersion) {
        qDebug() << "Plugin: \n" << pluginVersion->GetVersion() << "\n"
                 << "Location: " << qmlPlugin.fileName();
    } else {
        qDebug() << "Can't obtain version information from the plugin";
    }
}


int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;

    QString path = "C:/Workspace/QT/QMLImport/qml/";
  
    LoadPlugin(path);

    const QUrl url(QStringLiteral("qrc:/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
        &app, [url](QObject *obj, const QUrl &objUrl) {
            if (!obj && url == objUrl)
                QCoreApplication::exit(-1);
        }, Qt::QueuedConnection);

    engine.addImportPath(path);

    engine.load(url);

    return app.exec();
}

Here the Plugin´s header file including NameListInterface.h:

#ifndef NAMELISTPLUGIN_H
#define NAMELISTPLUGIN_H

#include <QObject>
#include<QQmlApplicationEngine>
#include "Person.h"
#include <QtQuick/QQuickView>
#include <QGuiApplication>
#include <QDebug>
#include <QQmlExtensionPlugin>
#include<QQmlContext>


class NameListInterface{
public:
    virtual const QString GetVersion() const = 0;
    virtual ~NameListInterface() {}
};
#define NameListInterface_iid "com.NameListPlugin"
Q_DECLARE_INTERFACE(NameListInterface, "com.my.NameListInterface")

class NameListPlugin : public QQmlExtensionPlugin, public NameListInterface
{
    Q_OBJECT
    Q_INTERFACES(NameListInterface)
    Q_PLUGIN_METADATA(IID NameListInterface_iid)

public:
    explicit NameListPlugin(QObject *parent = nullptr);

    void initializeEngine(QQmlEngine *engine, const char *uri);
    void registerTypes(const char *uri);

    // interface Implementation
    const QString GetVersion() const;


    // QML Extension plugin implementation
    //...

#endif // NAMELISTPLUGIN_H