Oracle Messages

ERRORLevel string cannot be added to the hierarchy; the specified parent level string is already the parent of string
CAUSEThe level specified as the parent in the ADD_LEVEL_TO_HIERARCHY procedure could not be used, because it was the parent of another level within the hierarchy.
ACTIONIn the ADD_LEVEL_TO_HIERARCHY procedure, specify a parent that is not already a parent of another level within a hierarchy.