Unhandle exception Error at Qt project using ui file

[citix]

I have 2 class(and 2 cpp file) and 1 ui file at my project. I define comboboxes and buttons at my ui file. I want to use ui file in both 2 class files. I can use ui and buttons and combobox at one of the class(cpp file) with the code "Ui::ProjectQtClass *ui;" but I cant use ui file and its objects at second class file with using the code "Ui::ProjectQtClass *ui;" because of unhandle exception error. How can I solve the problem ?

[ChrisW67]

You could start by posting the actual error, relevant parts of your actual code, and the stack backtrace at the time of failure.