DFF is not created when using value set with validation type "Table"

Summary

DFF not created when using value set with validation type "Table"

Content

Creating DFF to show department values on requisition page.

create a value set with validation type "Table". Using table "Per_Departments" to fetch "Name" whose datatype is varchar2(240).

create a DFF for Requisition header and use the value set. When trying to save DFF getting following error --

The value set KC_DEPTS cannot be assigned to the global segment Dept. (FND-2627) In application 10071 and descriptive flexfield POR_REQUISITION_HEADERS, value set KC_DEPTS cannot be assigned to global segment Dept which uses column ATTRIBUTE2. The assigned value set must have a data type that is compatible with the column data type and its maximum length must be no longer than the column length and its validation type must not be view object.