SSRS parameter not refreshing

I Having a problem getting query-based parameters to refresh in SSRS when the View Report or Refresh button is clicked.

First my data source from SSAS and i wanted to cascading between BU and GM. So I have 2 dataset Param_BU and Param_GM

for Param_BU the code is

 WITH  MEMBER [Measures].[ParameterCaption] AS [BUSINESS
 UNIT].[Business Unit Hierarchy].CURRENTMEMBER.MEMBER_CAPTION  MEMBER
 [Measures].[ParameterValue] AS [BUSINESS UNIT].[Business Unit
 Hierarchy].CURRENTMEMBER.UNIQUENAME MEMBER 
 [Measures].[ParameterLevel] AS [BUSINESS UNIT].[Business Unit
 Hierarchy].CURRENTMEMBER.LEVEL.ORDINAL  SELECT
 {[Measures].[ParameterCaption], [Measures].[ParameterValue],
 [Measures].[ParameterLevel]} ON COLUMNS  ,FILTER( [BUSINESS
 UNIT].[Business Unit
 Hierarchy].ALLMEMBERS,[Measures].[ParameterCaption]<>null) ON ROWS
 FROM [Model]

and for the dataset Param_GM

WITH 
MEMBER [Measures].[ParameterCaption] AS [BUSINESS UNIT].[GM Area Desc].CURRENTMEMBER.MEMBER_CAPTION 
MEMBER [Measures].[ParameterValue] AS [BUSINESS UNIT].[GM Area Desc].CURRENTMEMBER.UNIQUENAME 
MEMBER [Measures].[ParameterLevel] AS [BUSINESS UNIT].[GM Area Desc].CURRENTMEMBER.LEVEL.ORDINAL
SELECT {[Measures].[ParameterCaption], [Measures].[ParameterValue], [Measures].[ParameterLevel]} ON COLUMNS , 
[BUSINESS UNIT].[GM Area Desc].ALLMEMBERS ON ROWS
FROM (select StrToSet(@Param_BU,Constrained) on columns from [Model])

I already set at Parameter on dataset Param_GM but the there is an error said "The query contains the Param_BU parameter, which is not declared."

I already tried to closed the program and restart the computer, but nothing works.

Please help

Solution

Do you have the parameter matched up with the parameter in the Dataset Properties' Parameters tab?