How can I choose UI selectors for Element Exist activity

I am using the element exists activity but I believe the UI selectors for it are not functioning properly. When I click on edit selector though it brings this up image
and I am unable to confirm what element it is looking at. How can i get around this problem?

Click on the activity shown indicate item
Or retireve it from stanalone UiEplorer opened by Design>UiExplorer on top Main Menu

In your case (Screenshot above) no selector is specified