@JonB Thanks for pointing that out, I completely missed it. I'll go with PySide2 until more features are released in Qt6 like you mentioned. Thanks again.

@J.Hilk I think it was just an error while re-writing my code. My dev computer has no internet connection. I was supposed to use qstr

@Jason-Wright Thanks for your solution. Help me solve the same problem. You can also remove 'as Components', then don't care this alias when use your 'Navigation'.

...crickets?

I still had to remove the QWidget.. it's useless this way. My error was that I can't have a QWidget class without a QQmlApplicationEngine.

@vishnu From subfolder to main folder : i do it like this import "../subfolder" But on reverse i am confused what to do. How about import "../" ?

@JKSH said: The QQmlApplicationEngine runs code in the thread which constructed it. Thank you very much!