Thread: Error: Unable to set the XValues property of the Series class

I am trying to debug code written a couple years ago by someone other than me. The code is below. I am trying to loop through several worksheets and update a chart on each sheet. I get the error, "Unable to set the XValues property of the Series class".

Sub Vlookup_formula_histogram()
'
' Vlookup_histogram Macro
' Macro recorded 11/6/2009 by richarm1
'

'
Dim State As String
Dim chtObj As ChartObject

For i = 1 To Worksheets(SheetA).Range("B3").Value 'Number of state and company combos
    
    If Worksheets(SheetB).Cells(i + 1, 6) = Worksheets(SheetA).Range("B5") Then
    
    State = Worksheets(SheetB).Cells(i + 1, 1)
    
    'Copy and drag the histogram formula
    Sheets(Worksheets(SheetB).Cells(i + 1, 1).Value).Select
    Range("S4").Select
    ActiveCell.FormulaR1C1 = "=VLOOKUP(RC[-1],R2C69:R23C70,2)"
    Range("S4").Select
    Selection.AutoFill Destination:=Range("S4:S" & Sheets(Worksheets(SheetB).Cells(i + 1, 1).Value).Range("X3").Value + 3)
    
    For Each chtObj In Sheets(State).ChartObjects
    
        'Change the formula for the chart
        chtObj.Activate
        ActiveChart.SeriesCollection(1).XValues = "=" & State & "!R2C70:R23C70"
        ActiveChart.SeriesCollection(1).Values = "=" & State & "!R2C71:R23C71"
        'ActiveChart.HasTitle = True
        'activechart.ChartTitle.Text =
    Next

    End If
Next i

End Sub

Here is the line that is the culprit for the error:

ActiveChart.SeriesCollection(1).XValues = "=" & State & "!R2C70:R23C70"

Any ideas of why I might get this error and how I might fix it? Thanks!