I have answered the same question recently (but cannot find it).
This is a bug (I logged it, but got no feedback). If you insert that slide as Ready-to-go slide from the project, you cannot edit the text in the states. It is a very weird bug but I found a workaround:
Open the project Wired as project
Find the slide 'Click and Reveal 05' and copy it to the clipboard from the Filmstrip
Switch to your project, go to the Filmstrip and paste the slide
You will see that you are now able to edit all the objects in the states. I am talking about the text captions, both the main caption and the added text caption (red border).