Hi, I'm trying to call a method with a null value in IF statement: =Iif(IsNothing(Sum(Fields!BuildTypeInt.Value, "TestExecutions")),"Not Defined",Enums.Parse.IntValueToString(Sum(Fields!BuildTypeInt.Value, "TestExecutions"))) I mean, I need to call the method only if the value is not null, But, I can see that even if the value is null the expression looks at Enums.Parse.IntValueToString(Sum(Fields!BuildTypeInt.Value, "TestExecutions")) and returns #Error. Can you please help me solve this issue? Regards, Bader