Creating a range from several ranges in excel vba - vba

Question

I have a worksheet with a matrix, which is divided diagonally with a cell that is black. The matrix contains the same header, both vertically and horisontally.
The idea is that you show the relation between the items in the bottom area, below the diagonal.
I want to create a Range (MatrixRange) that is the bottom part of the area.
What I'm trying to do is create a range for each column that I use, and add it to the MatrixRange. The different ranges im trying to combine is therefore of different height.
Dim MatrixRange As Range
Private Sub Workbook_Open()
Dim n As Integer
Dim NextRange As Range
Dim OldRange As Range
Dim ws As Worksheet
Set ws = Sheets("Systemmatrise")
With ws
For n = 1 To 68
Set OldRange = MatrixRange
Set NextRange = .Range(Range("B9").Offset(n + 1, n), Cells(78, n + 2))
Set MatrixRange = Union(OldRange, NextRange)
Next n
End With
Debug.Print MatrixRange
End Sub
I get a "Runtime error 5" after
Set MatrixRange = Union(OldRange, NextRange)
Is there an easier way to create this Range, or somehow to fix this problem?
Thanks in advance

Answer 1

You don't seem to set an initial range for OldRange, so it'll be Nothing during the first iteration - the likely cause of your error.
Delete this line:
Set OldRange = MatrixRange
Correct this line to include a dot in front of Cells:
Set NextRange = .Range(Range("B9").Offset(n + 1, n), .Cells(78, n + 2))
and before the For Loop, add this (extra dot noted, thanks Jeeped):
Set OldRange = .Range(.Range("B9").Offset(1,0), .Cells(78, 2))