Place the cursor on a selected field

What causes this issue?

Maintaining column headers for fields is possible only for selected
fields.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

First, choose the field by selecting the left checkbox. Then, place the
cursor on the field and choose the function for maintaining column
headers again.

Error message extract from SAP system. Copyright SAP SE.