The attached QtCreator project startet from a new, empty Qt Quick application.

In the main.cpp we added

QGuiApplication::setAttribute(Qt::AA_PluginApplication);

In main.qml, we added

import QtQuick.Dialogs 1.3
...
FileDialog{}

When we run this project we see a crash while quitting the application in [QCocoaMenuLoader dealloc]   ->  see crashlog.txt .

When we remove the line

QGuiApplication::setAttribute(Qt::AA_PluginApplication);

everything is fine. If we remove the FileDialog from main.qml, the crash is gone,too.

The context, where we observe the same crash is in an audio plugin, done with QtQuick. Here we set

QGuiApplication::setAttribute(Qt::AA_PluginApplication); QGuiApplication::setAttribute(Qt::AA_DontUseNativeMenuBar); 

Quitting the plugin's host application causes the same crash. In the plugin if we

• remove the two setAttribute() calls, the host always crashes in [QCocoaMenuLoader dealloc] 
• remove the FileDialog and do set the two attribute, the host quits fine