Place the cursor on a field which can accept input

What causes this issue?

You are editing the columns of a table control and chose one of the
following functions:
- Attributes
- Create element
- Insert from temporary storage.
However, the cursor is not in a field for the name of a column element
or header for a column element or the field is not an input field.

System Response

The system cannot assign the function to any screen element.

How to fix this error?

Place the cursor on a suitable field and repeat the function.
You can only create headers for column elements if the table control
has the attribute 'with column headers'.

Error message extract from SAP system. Copyright SAP SE.