Diagnosis
You tried to give the current document title a name, which alreadyexists for another document.

Procedure
To make the necessary correction, first press the return key.
If you are in the drilldown report area of the Editorial Workbench andwant to carry out data transfer, first copy a selected text as thetitle.
If you are already in editing, then choose the tab page "attributes".Here you can change the title manually.