Diagnosis
You tried to remove a set field from the archive information structure.

System Response
There are usually fields in a field catalog which are not flagged as"valid". These fields are normally key fields which are automaticallyincorporated into the info structure and cannot be deleted.
All valid fields which are marked have been removed from the infostructure.

Procedure
Only remove those fields which are not flagged as "fixed". Ifnecessary, use a different field catalog.