Diagnosis
You want to convert screen elements within a selected rectangular areato checkboxes or radio buttons.
Not all future checkboxes, radio buttons or associated field texts havefield names.

System Response
The system needs the field name to be able link a checkbox or radiobutton to its field text. Fields of the same name belong together.
Elements with no name cannot be converted to checkboxes or radiobuttons.

Procedure
Assign a field name to the elements you want to convert. You can dothis on the "Attributes" screen or in all field list views.