This is a great tool for finding those "hidden" objects, which get tucked underneath during page creation.
Incomplete Elements is a button on your Page Designer menu. Click this to highlight any empty text or image boxes.
You will see the orange ball handles highlight on those elements and you can delete them or edit from there.
HINT: When using templates that have existing text such as a Headline, you may see that text box highlight as INCOMPLETE. If this happens, simply click inside the text box, add a character, delete the character, and save the text box.
You've now edited the box and it's no longer incomplete.