Making graph - run-time error 424 - Object required - excel

Question

I am trying to make a graph using the following VBa code. But I am getting a Run-time error 424 - Object required at the row:
Set rngChtXVal = .Columns(1).Offset(1).Resize(.Rows.Count - 1)
What is going wrong?
Sub MakeGraph()
Dim myChtObj As ChartObject
Dim rngChtData As Variant
Dim rngChtXVal As Variant
Dim iColumn As Long
sel= Sheets("Data").Range(Cells(1, 1), Cells(200, 2))
rngChtData = sel
' define chart's X values
With rngChtData
Set rngChtXVal = .Columns(1).Offset(1).Resize(.Rows.Count - 1)
End With
' add the chart
Set myChtObj = ActiveSheet.ChartObjects.Add(Left:=250, Width:=425, Top:=10, Height:=240)
With myChtObj.Chart
' make an XY chart
.ChartType = xlLine
' remove extra series
Do Until .SeriesCollection.Count = 0
.SeriesCollection(1).Delete
Loop
' add series from selected range, column by column
For iColumn = 2 To rngChtData.Columns.Count
With .SeriesCollection.NewSeries
.Values = rngChtXVal.Offset(, iColumn - 1)
.XValues = rngChtXVal
.Name = rngChtData(1, iColumn)
End With
Next
End With
End Sub

Answer 1

You've named rngChtData and rngChtXVal like Range objects, but you've declared them as Variant. While Variants can be Ranges, it makes debugging your code much harder. Use explicit variable types whenever possible. To resolve your issue, change your code like this:
Sub MakeGraph()
Dim myChtObj As ChartObject
Dim rngChtData As Range
Dim rngChtXVal As Range
Dim iColumn As Long
With Sheets("Data")
Set rngChtData = .Range(.Cells(1, 1), .Cells(200, 2))
End With
' define chart's X values
With rngChtData
Set rngChtXVal = .Columns(1).Offset(1).Resize(.Rows.Count - 1)
End With