Error "Invalid Parameter" in Charting VBA Code

Been trying to figure out what the reason caused the "Invalid Parameter" error for the past 20 minutes... and still clueless. Anyway, In my worksheet I have 2 charts. In my VBA code, I defined both chart with individual seriescollection (SeriesCollection(1) for chart one and SeriesCollect(2) for chart two). However, I kept getting the Invalid Parameter at line ChtObjTELCO.Chart.SeriesCollection(2).Values = Range(Cells(UserRow, 8), Cells(UserRow, 9)) and to be honest, I can't figure it out why.

Any help is appreciated.

Below is my code and I have attached a sample workbook

Sub UpdateChart()
Dim ChtObjEnt As ChartObject, ChtObjTELCO As ChartObject
Dim UserRow As Integer

    Set ChtObjEnt = ActiveSheet.ChartObjects(1)
    Set ChtObjTELCO = ActiveSheet.ChartObjects(2)
    UserRow = ActiveCell.Row

If UserRow < 19 Or IsEmpty(Cells(UserRow, 3)) Then
    ChtObjEnt.Visible = False
Else
    ChtObjEnt.Chart.SeriesCollection(1).Values = Range(Cells(UserRow, 3), Cells(UserRow, 4))
    ChtObjEnt.Chart.ChartTitle.Text = Cells(UserRow, 1).Text
    ChtObjEnt.Visible = True
    ChtObjTELCO.Chart.SeriesCollection(2).Values = Range(Cells(UserRow, 8), Cells(UserRow, 9)) 'Error Line
    ChtObjTELCO.Chart.ChartTitle.Text = Cells(UserRow, "F").Text
    ChtObjTELCO.Visible = True
End If
End Sub