Diagnosis
On the item overview, you have chosen a function for editing ordisplaying one or more items, but have not selected any items.

Procedure
Select the item(s) you want to edit or display. Either enter "x" in theselection list or place the cursor on the appropriate line(s) and pressfunction key F9. Then choose your function again.
You also have the option of selecting all the items in one step. To dothis, choose menu function Edit --> Select --> Selectall.