Message Oracle ORA-36636 - (XSDUNION04) The unique concat dimension workspace object cannot be changed to NOT UNIQUE, because it is a base of at least one other unique concat dimension.

ERROR	(XSDUNION04) The unique concat dimension workspace object cannot be changed to NOT UNIQUE, because it is a base of at least one other unique concat dimension.
CAUSE	A non-unique concat dimension cannot be used as a base of a dependent unique concat.
ACTION	CHGDFN any dependent unique concat dimensions to NOT UNIQUE and retry.