Settings for incompletion and for field control do not match

What causes this issue?

The combination of data for checking incompletion and field control is
inconsistent.

System Response

The system issues a warning.

How to fix this error?

Check your entry.

How can this happen?

An example of an inconsistent entry would be setting the incompletion
check for a field in a declaration type but to set the field control to
' ' or '0' so that the field is hidden during maintenance transactions.
An example of an unsuitable combination would be to set field control
to '2' so that the field is obligatory during the maintenance
transactions but not to select this field for the declaration type so
that is not checked during document selection.
In addition, if the on-line system response field is maintained with
'E' but not selected for an incompletion check for the declaration
type, a warning is issued.
A warning is also issued if the system checks for incompletion in one
goods direction only, for example, export, but the field control has
been maintained as an obligatory field for import documents as well.

Error message extract from SAP system. Copyright SAP SE.