Announcing that this problem is solved. I am really appreciate and grateful to your suggestions and advice, after all the segment fault is no more occur. 🙏🏻. It troubles me for around a week.

@suslucoder Then mark the topic as solved.

@aha_1980 i cleaned my old project build tried it again. The build is successful but when i try to run same error as mentioned above. any changes : just uninstalled Qt5.9.1 .other than that nothing much. this is my compiler tab if it helps any !! [image: f0224abb-fb05-4190-8409-4c859082c261.PNG] p.. i have downloaded windows 10 SDK too now there is no triangle on msvc 32bit one but the problem still remains :/ .

@SGaist Thanks!

Like @kshegunov already wrote using singleton should be avoided when possible and your use case really does't need any singleton. It sounds that you are rather creating tight coupling between your different classes rather that have a lean path to use system tray. So what are all these classes doing with the system tray icon and that menu ?