008D8EE2 You cannot modify the value of an RMS key field that
    does not allow changes.

    Explanation:

    Some RMS key fields are defined so that once a value is stored in
    the field it cannot be changed.

    User Action:

    Since you cannot change the value of the field, the only way to
    have a record with that change is to erase the old record and
    store a new one. It is better to store before you erase the old
    record. If you made the change accidentally at a *.prompt, then
    retype the query and press TAB and RETURN at that prompt. You can
    find out which fields are keys by entering a SHOW FIELDS command.