Howto delete Widget from ui designer correctly

[TJSonic]

I have created lineEdit and progressBar widgets in UI designer, then compiled an application.
All was working fine. Then i desided to delete this widgets from UI designer. After compiling app does not starts. I think i deleted those widgets wrong. So how to delete widget from UI designer correctly?:(

[squidge]

define "app does not starts"

[TJSonic]

Sloved. All that i had to do is to delete ui_mainwindow.h