Message Oracle ORA-36650 - (XSDUNION10) Concat dimension workspace object cannot be changed to UNIQUE. Leaves workspace object and workspace object share the value number.

ERROR	(XSDUNION10) Concat dimension workspace object cannot be changed to UNIQUE. Leaves workspace object and workspace object share the value number.
CAUSE	Unique concat base dimensions cannot contain duplicate values.
ACTION	Use MAINTAIN RENAME to change one of the duplicate values and retry.