I'm new in MDX so I have problem with simple query.My Query is: Code:select {[Measures].[KLUCZ]} ON COLUMNS, {[JEDNOSTKA_NA].members, [JEDNOSTKA_Z].members} ON ROWS from KLUCZE I had this error: The following is not a valid MDX Query: Mondrian Error:All arguments to function '{}' must have same hierarchy This query is OK: Code:[code]select {[Measures].[KLUCZ]} ON COLUMNS, {[JEDNOSTKA_NA].members} ON ROWS from KLUCZE Please help me.