Entity Relationship Properties update via business rules

Hi Team,

I would like to fetch and update the Entity Relationship Properties for the Entity Dimension members via Business Rules.

The below peace of code works fine for only when I pass the Actual and Budget but when i pass the other scenario Type like Scenariotype 1 to 8   I get the error Object is not set to an instance of an object.

Dim Scenario As String = args.CustSubstVarsAlreadyResolved("Param_SecnarioType_EO_24")

'The above value i get it from the combo box as delimited list

 Dim Scenarioid As Integer = BRApi.Finance.Members.GetMemberId(si,dimtype.Scenario.Id,Scenario)
Dim MyScenarioTypeid As ScenarioType = BRApi.Finance.Scenario.GetScenarioType(si,Scenarioid)
Dim Timefilter As String = args.CustSubstVarsAlreadyResolved("Param_Time_24")
Dim Timeid As Integer = BRApi.Finance.Members.GetMemberId(si,dimtype.Time.Id,Timefilter)

Can you please help me with the correct way to get the scenario Type.