Passing Named Range as parameter to Sub()

HI,

I am trying to pass a parameter, a named range on another sheet, to a secondary Sub(). The named range is Slist and it is on a sheet called Setup. In my main Sub() I define

Dim MenuList As Range
Set MenuList = ThisWorkbook.Sheets("Setup").Range("SList")

and call the secondary Sub() as

Call Add_Drop_Down_Menu_Cell(MenuList)

My secondary Sub() is

Sub Add_Drop_Down_Menu_Cell(MenuList As Range)
    With ThisWorkbook.Sheets("MenuData").Range("B5").Validation
        .Delete
        .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:=xlBetween, Formula1:="=MenuList"
        .IgnoreBlank = True
        .InCellDropdown = True
        .InputTitle = ""
        .ErrorTitle = ""
        .InputMessage = ""
        .ErrorMessage = ""
        .ShowInput = True
        .ShowError = True
    End With
End Sub

I am getting application-defined or object defined error 1004. It appears that the Sub cannot locate or access my MenuList. Is there a way I can check that a correct menu list is being passed tot he Sub? Also, any ideas how to fix this? Thank you.