Diagnosis
You tried to maintain an additional field that was already defined, butyou chose a different table assignment in the logical database than inthe original definition of the additional field.

Procedure
If you want to change the definition of the additional field withoutchanging the assignment to the database table, define the correctdatabase table.
If you want to assign the additional field to a different databasetable, you must first delete the additional field and then define itagain.