Quote Originally Posted by ChrisW67 View Post
Run the program in a debugger. When it crashes inspect the backtrace and the value of variables in use at the time.

What set "list" in ConversationWindow and what is its value? I am betting it is null or invalid.
Thank you, the error was that I forgot to parse my list from MainWindow to EditWindow pointer variable.

I'm still learning second day with Qt & C++ lol.