SAP Message QS337 - The "copy" function is not supported for this row

Diagnosis
You have positioned the cursor between two fields or on a line whichdoes not support the function Copy .
You can only copy selected sets with this function in the currentlist.

System Response
The function was not performed.

Procedure
If you want to select a selected set, you must position the cursor in afield on a selected set line before calling the function.