Widget object name is not accessible using intellisense in the editor

I did the following,

1. Created a widget app

2. Drag and dropped a pushbutton in the ui form.

3. navigated to its .cpp file and tried to access ui->pushbutton, but intellisense failed to find this pushbutton

4. Rebuilt the project, again tried to access ui->pushbutton, but intellisense again failed to find this pushbutton.
5. Restarted Qt Creator, now intellisense found the pushbutton .