diff --git a/Linphone/core/App.cpp b/Linphone/core/App.cpp
index 11e1e1527..a65712945 100644
--- a/Linphone/core/App.cpp
+++ b/Linphone/core/App.cpp
@@ -86,6 +86,7 @@ void App::init() {
 		qDebug() << "[App] Starting Thread";
 		mLinphoneThread->start();
 	}
+	setQuitOnLastWindowClosed(true); // TODO: use settings to set it
 
 	// QML
 	mEngine = new QQmlApplicationEngine(this);
@@ -148,6 +149,10 @@ void App::initCppInterfaces() {
 
 void App::clean() {
 	// Wait 500ms to let time for log te be stored.
+	delete mNotifier;
+	mNotifier = nullptr;
+	delete mEngine;
+	mEngine = nullptr;
 	mLinphoneThread->wait(250);
 	qApp->processEvents(QEventLoop::AllEvents, 250);
 	mLinphoneThread->exit();
diff --git a/Linphone/core/App.hpp b/Linphone/core/App.hpp
index 0951e6bbb..afd9f6f4b 100644
--- a/Linphone/core/App.hpp
+++ b/Linphone/core/App.hpp
@@ -76,6 +76,8 @@ public:
 	QQmlApplicationEngine *mEngine = nullptr;
 	bool notify(QObject *receiver, QEvent *event);
 
+	enum class StatusCode { gRestartCode = 1000, gDeleteDataCode = 1001 };
+
 private:
 	void createCommandParser();
 
diff --git a/Linphone/core/notifier/Notifier.cpp b/Linphone/core/notifier/Notifier.cpp
index cf6363ae0..538a09ef1 100644
--- a/Linphone/core/notifier/Notifier.cpp
+++ b/Linphone/core/notifier/Notifier.cpp
@@ -118,9 +118,11 @@ Notifier::~Notifier() {
 	delete mMutex;
 
 	const int nComponents = Notifications.size();
-	for (int i = 0; i < nComponents; ++i)
-		mComponents[i]->deleteLater();
-	delete[] mComponents;
+	if (mComponents) {
+		for (int i = 0; i < nComponents; ++i)
+			if (mComponents[i]) mComponents[i]->deleteLater();
+		delete[] mComponents;
+	}
 }
 
 // -----------------------------------------------------------------------------
diff --git a/Linphone/main.cpp b/Linphone/main.cpp
index fcd63346a..c10cd7432 100644
--- a/Linphone/main.cpp
+++ b/Linphone/main.cpp
@@ -46,9 +46,10 @@ int main(int argc, char *argv[]) {
 #endif
 
 	int result = 0;
-	while (result >= 0) {
+	do {
 		result = app.exec();
-	}
+	} while (result == (int)App::StatusCode::gRestartCode);
+	qWarning() << "[Main] Exiting app with the code : " << result;
 	app.clean();
 	return result;
 }
diff --git a/Linphone/tool/thread/Thread.cpp b/Linphone/tool/thread/Thread.cpp
index af126279d..2daca432d 100644
--- a/Linphone/tool/thread/Thread.cpp
+++ b/Linphone/tool/thread/Thread.cpp
@@ -44,7 +44,8 @@ bool Thread::mustBeInLinphoneThread(const QString &context) {
 }
 
 bool Thread::mustBeInMainThread(const QString &context) {
-	bool isMainThread = QThread::currentThread() == App::getInstance()->thread();
+	if (!qApp) return true;
+	bool isMainThread = QThread::currentThread() == qApp->thread();
 	if (!isMainThread) qCritical() << "[Thread] Not processing in Main thread from " << context;
 	return isMainThread;
 }