Element already exists (edit with 'Attributes' function)

What causes this issue?

When editing the column elements of a table control or tab control, you
chose Create element, but the cursor is on an element which already
exists.

System Response

Creation of element rejected.

How to fix this error?

If you want to maintain the element, choose "Attributes".
If you want to create a element, place the cursor on a space for an
element which does not exist and repeat the "Create element" function.

Error message extract from SAP system. Copyright SAP SE.